Systematic relationships of the palaeogene family Presbyornithidae ...

Zoological Journal of the Linnean Society (1997), 121: 429–483. With 37 figures 

Systematic relationships of the palaeogene 

family Presbyornithidae (Aves: Anseriformes) 

PER G. P. ERICSON, F.L.S. 

Swedish Museum of Natural History, P.O. Box 50007, S-104 05 Stockholm, Sweden 

Received May 1996; accepted for publication March 1997 

The early Tertiary (Paleocene and Eocene) family Presbyornithidae is one of the most 

completely known group of fossil birds. Essentially all parts of the skeleton are represented 

in the fossil record, allowing a thorough analysis of the phylogenetic position of the family. 

Forty-two families of nonpasserine birds representing the orders Ciconiiformes, Anseriformes, 

Galliformes, Gruiformes and Charadriiformes, were included in a cladistic analysis of 71 

skeletal characters. The previously suggested anseriform affinity of the Presbyornithidae was 

confirmed. Furthermore, the family proved to be closer to the Anatidae than to the Anhimidae 

or Anseranatidae. The many postcranial similarities with certain charadriiform birds as the 

Burhinidae, obviously are plesiomorphies. By this observation, a better undestanding of 

character evolution in nonpasserine skeletal morphology is gained. The often suggested close 

relationship of anseriform and galliform birds is not confirmed by osteology. Instead, the 

Anseriformes and the Phoenicopteridae form a monophyletic clade that is the sister to the 

remaining ciconiiform birds. This result renders the Ciconiiformes sensu Wetmore (1960) 

polyphyletic. 

© 1997 The Linnean Society of London 

ADDITIONAL KEY WORDS: — systematics – cladistic analysis – osteology – fossil birds 

– Aves – nonpasserines – Presbyornithidae – Presbyornis. 

CONTENTS 

Introduction . . . . . . . . . . . . . . . . . . . . . . . 430 

History of classification of the Presbyornithidae . . . . . . . . . . 430 

The Presbyornithidae—a mosaic morphology . . . . . . . . . . 432 

Material . . . . . . . . . . . . . . . . . . . . . . . . 434 

Methods . . . . . . . . . . . . . . . . . . . . . . . . 434 

General position of the family Presbyornithidae . . . . . . . . . . . 435 

Selection of ingroup taxa . . . . . . . . . . . . . . . . . 435 

Outgroup . . . . . . . . . . . . . . . . . . . . . . 436 

Character selection . . . . . . . . . . . . . . . . . . . 436 

Character descriptions . . . . . . . . . . . . . . . . . . 437 

Results . . . . . . . . . . . . . . . . . . . . . . . 462 

Relationships of the Presbyornithidae within the Anseriformes . . . . . . 466 

Character selection . . . . . . . . . . . . . . . . . . . 467 

Character descriptions . . . . . . . . . . . . . . . . . . 467 

Results . . . . . . . . . . . . . . . . . . . . . . . 474 

Discussion . . . . . . . . . . . . . . . . . . . . . . . 476 

429 

0024–4082/97/120429+55 $25.00/0/zj970098 © 1997 The Linnean Society of London

430 

P. G. P. ERICSON 

Acknowledgements . . . . . . . . . . . . . . . . . . . . 479 

References . . . . . . . . . . . . . . . . . . . . . . . 479 

Appendix . . . . . . . . . . . . . . . . . . . . . . . . 482 

INTRODUCTION 

In 1926, Alexander Wetmore described a new genus and species of charadriiform 

bird from the Early Eocene of Utah, Presbyornis pervetus, that he (Wetmore 1926:398) 

supposed to be “typical of an ancestral stock, from which existing Avocets and Stilts 

have descended”. He erected a new family for it, Presbyornithidae. 

Almost 30 years later, Hildegarde Howard (1955) published a description of 

Telmabates antiquus, a likewise Early Eocene bird collected in Argentina by George 

Gaylord Simpson in 1930–1. Howard regarded this species a primitive flamingo 

and she erected the family Telmabatidae. A second, smaller species, Telmabates 

howardae, was described by Cracraft (1970) from the same collection. 

In 1970, a field party led by Paul McGrew of the University of Wyoming collected 

vertebrate fossils at the Bird Quarry locality in Wyoming. A large number of bird 

fossils were found, of which most were identified as Presbyornis sp. Given that the 

original description by Wetmore (1926) was based on very scanty and poorly preserved 

material, this new material considerably increased the anatomical information of 

Presbyornis (Feduccia & McGrew, 1974). These authors also were the first to draw 

attention to the similarity between Presbyornis and Telmabates, which they synonymized 

(Telmabates howardae was regarded as conspecific with Presbyornis pervetus). 

Although the postcranial skeleton of the Presbyornithidae sensu Feduccia & 

McGrew (1974), was fairly well known in the early 1970s, the cranium was less so. 

A few skull fragments of Telmabates had been found but were given little attention 

by Howard (1955:4–5). It thus was surprising when Feduccia and McGrew (1974: 

50) associated the long-legged postcranial skeleton with the clearly duck-like braincases 

and bills they had collected at the Bird Quarry locality, which were poorly 

preserved, however. It was not until Storrs L. Olson, Robert J. Emry and Arnold 

Lewis (Smithsonian Institution), in 1977 and 1979 made a collection of slabs 

containing thousands of bones gathered in a thin stratum from another Eocene 

Wyoming locality, Canyon Creek Butte, that good cranial material became available. 

Today, large quantities of fossils tentatively referred to as Presbyornis sp. have been 

collected at several localities in Utah, Wyoming and Colorado, as well as in Argentina 

and Mongolia. Taken together, all these collections give a clear picture of the skeletal 

anatomy of Presbyornis (Fig. 1). 

History of classification of the Presbyornithidae 

Wetmore (1926) thought the Presbyornithidae to be close to the Recurvirostridae 

(Charadriiformes). Without knowing about its closer relationship with Presbyornis, 

Howard (1955:3) regarded Telmabates as a primitive flamingo (Phoenicopteridae) 

with anseriform modifications. Actually, she found only minor similarities to the 

charadriiforms which she believed should be considered primitive (op.cit. p.5). 

Cracraft (1970:480) obviously agreed with Howard’s phylogenetic interpretation 

after having re-examined the Telmabates collection at AMNH. In 1976, Harrison 

and Walker (1976:335) preferred to view Telmabates as an early anseriform bird with

SYSTEMATIC POSITION OF THE PRESBYORNITHIDAE 431 

Figure 1. Anatomical reconstruction of Presbyornis sp. After Olson & Feduccia (1980b). 

“some similarities to other birds including phoenicopterids” that was best placed in 

the order Anseriformes. They did so although it was acknowledged that Telmabates 

might not be possible to allocate to a modern order given it shared the skeletal 

morphology not only with the flamingos and anseriforms, but with ibises and 

charadriiform birds too. 

Feduccia and McGrew (1974) stressed a close affinity of the Presbyornithidae 

with the Phoenicopteridae. Their argument rested on at least three observations. 

First, the new material from the Bird Quarry locality was very similar to Telmabates 

(already assumed to be a primitive flamingo by Howard [1955]). Second, the fossils, 

including egg-shells tentatively referred to this bird, were collected at a locality once 

situated at the shore of a very shallow, and obviously saline, Early Eocene lake, i.e. 

a habitat similar to that preferred by modern flamingos. Third, the presence of a 

‘Green River flamingo’ had been predicted by Wetmore a few years earlier when 

he allocated Eocene bird tracks to this group (see Kahl, 1970:294). 

In 1976, Feduccia elaborated the anatomical evidence for a close evolutionary 

relationship between the Presbyornithidae (including Telmabates), flamingos, shorebirds 

and ducks. He suggested that the flamingo link the shorebirds to the ducks,

432 


Shorebirds Recurvirostrids Flamingos Anseriforms 

Presbyornis 

Figure 2. Evolutionary relationship between various shorebirds, flamingos, and anseriform birds, 

suggesting that Presbyornis was the ancestor of both flamingos and ducks. Redrawn after Feduccia 

(1976). 

and placed the Presbyornithidae on the evolutionary lineage leading to the flamingos 

and ducks, after the shorebirds had branched off, and after the skull had become 

typically anseriform (Fig. 2). The implication was that flamingos branched off from 

a long-legged anseriform stock, and thus evolved their peculiar feeding mechanism 

from an anseriform cranial morphology. 

Later, Feduccia (1977, 1978) placed the Presbyornithidae with the anseriforms at 

a point after the flamingos had branched off, suggesting that both flamingos and 

ducks evolved from the same stock of primitive shorebirds (Fig. 3). He still considered 

some characters, especially the V-shaped nasal-frontal hinge, to prove a close 

relationship between the Presbyornithidae and flamingos. Given that he now regarded 

the Presbyornithidae a temporal relict, not ancestral to the flamingos, the characters 

shared with the flamingos must have been possessed by their common, primitive 

shorebird ancestor (1978: fig. 5). 

By the late 1970s, when considerably more material of the Presbyornithidae had 

been collected, several well-preserved skulls became available for study. A photo of 

a skull still in matrix (Feduccia, 1978: fig. 4) shows the skull of Presbyornis to be even 

more duck-like than was previously realized. In fact, this observation might have 

been what lead Feduccia to abandon his earlier (1976) opinion that the Presbyornithidae 

were ancestral to the entire flamingo-duck complex. 

In 1980, two papers on this topic were published by Olson and Feduccia. In the 

first (1980a), the previously claimed ciconiiform affiliation of the 

flamingos (Reichenow, 1882; Fürbringer, 1888) was scrutinized and rejected in 

favour of a charadriiform relationship. Their second paper (1980b) evaluated and 

dismissed the sometimes proposed anseriform-galliform sistergroup relationship. 

Instead, they argued that the Anseriformes evolved from a primitive charadriiform 

stock (following Feduccia, 1978), and stressed the role of the Presbyornithidae as a 

true evolutionary link between the two orders. Additional presbyornithid material 

was presented, including a complete skull with well-preserved mandible, trachea 

and hyoid apparatus. This skull shows an extremely close resemblance to the 

Anatidae, especially the Australian genus Stictonetta (Olson & Feduccia, 1980b). 

The Presbyornithidae—a mosaic morphology 

The systematic position of the Presbyornithidae, and its contribution to the 

understanding of the evolution of birds, has been one of the most controversial


(c) 

Figure 3. The Presbyornithidae (b) are placed with the ducks (c) at a point after the flamingos (d) had 

already branched off, suggesting that both flamingos and ducks evolved from the same stock of 

primitive shorebirds (a). After Feduccia (1977). 

issues in higher-level systematics in recent years (Cracraft, 1980, 1981, 1988; 

Olson & Feduccia, 1980a, b; Olson, 1985; Raikow, 1981). The skeleton of the 

Presbyornithidae (Fig. 1) has been described as a mosaic, combining the head of a 

duck with the body of a shorebird, leading to the conclusion that the orders 

Anseriformes and Charadriiformes are closely linked (Feduccia, 1978; Olson & 

Feduccia, 1980b). The Presbyornithidae would then be a show-case of when fossils 

significantly contribute to the phylogenetic reconstruction of birds (Feduccia, 1978; 

Olson, 1985). 

Those who question the phylogenetic interpretation of the Presbyornithidae have 

focused mainly on two, closely related matters. First, do all fossils claimed to belong 

to this supposedly duck-headed, long-legged, avocet-like bird, really derive from a 

single taxon (Cracraft, 1980; Andors, 1988)? Secondly, given that this should be the 

case, how should such a morphology be interpreted? 

The first question is no longer an issue for discussion. There are too many 

localities known from where the only bird remains present consist of duck-like skulls 

associated with presbyornithid postcranial elements that bear a resemblance to 

Charadriiformes, to make an alternative explanation likely (Olson & Feduccia, 

1980b; pers. obs.). Furthermore, a partly articulated skeleton of a single individual 

(b) 

(d) 

(a)

434 


combining these skull and postcranial morphologies, has recently been discovered 

(pers. obs.). 

This paper deals only with the second problem: what is the systematic position 

of the Presbyornithidae? Hypotheses concerning relationships among other nonpasseriform 

families are generated by this study, but they will be commented upon 

only when they bear on the phylogenetic relationships of the Presbyornithidae. 

General discussions of the higher-level systematics of nonpasserine birds, based on 

the skeletal data presented herein, will be published elsewhere. 

MATERIAL 

Osteological data on extant and fossil taxa were collected primarily through 

studies of the extensive collections of the National Museum of Natural History, 

Washington D.C. (USNM). The Appendix lists examples of species possessing the 

character states assigned to the families. Of each family, samples of all genera and, 

in most cases, all species represented in the collection, were studied. Considerable 

effort was put into the study of the intra-family character variation, partly in order 

to define the character states properly, and partly to discover cases of polymorphisms. 

Some taxa that are poorly represented in the USNM collection, were studied in the 

collections of the American Museum of Natural History, New York (AMNH). 

Generally speaking, a character that in several instances shows intra-familial 

polymorphism is often less useful in the analysis of the relationships between families. 

Characters that exhibit a large degree of intra-familial variation in character states 

have intentionally been avoided in the analyses. The vast majority of the included 

characters have been unambiguously assigned their character states, however. In 

those cases where a family is polymorphic, it was assigned the most widespread 

character state within the family. It has been relatively easy to decide which is the 

most widespread state, given that alternate states typically are found in but a few 

species, or even individuals. Remarks on the observed polymorphisms are made in 

the character descriptions below. 

The character states of the Presbyornithidae have been determined after studying 

all known material collected in the United States and Argentina, up to 1990. A 

detailed description of the skeletal anatomy of the Presbyornithidae is in preparation. 

METHODS 

The relationships of the Presbyornithidae have been assessed by a cladistic analysis 

of the taxonomic distribution of certain skeletal characters where the favoured tree 

topology was chosen by applying the parsimony criterion. The analysis was performed 

in two steps. In the first, the general position of the Presbyornithidae within the 

Class Aves was determined. In the next, another data matrix was constructed, that 

partly included relevant characters from the first analysis, and partly new skeletal 

characters suitable to resolve branching patterns at this particular phylogenetic level. 

In this matrix, genera are used as terminal taxa (the Presbyornithidae are represented 

by the most well known genus, Presbyornis). 

The advantage of making the analysis in two steps is twofold. First, this reduces


the homoplasies (i.e. morphologies which have arisen independently due to parallelisms 

and reversals) in the matrix, and secondly, the size of the data matrix is 

decreased. The effect in both cases is that less computer power and time are required 

to run the algorithms used to estimate the most parsimonious solutions of the 

observed character states distribution. 

In the search for the most parsimonious solutions, the computer program Hennig86 

(Farris, 1988) was used (utilizing the Hennig86 commands mh∗ followed by bb∗). 

From the multiple most parsimonious trees a strict consensus tree was constructed 

by the command nelsen). Estimates of the support of the nodes in the consensus 

tree were obtained through Parsimony Jackknifing (Farris, 1995; Farris et al., 1996). 

Roughly speaking, these estimates serve as measures of how much faith one should 

have in the nodes. The estimates range between 0 and 1; the higher the value, the 

more support for the node. 

For some characters the transformations will appear differently on the trees 

depending on which optimization criterion is used. In this paper I have assumed 

that parallellisms are more common than reversals when viewing the Class Aves as 

a whole, and that reversals are more likely at lower taxonomic levels (for example 

within an order as in this case). In the second analysis the characters were optimized 

on the tree using the option ACCTRAN (accelerated transformation) in MacClade 

(Maddison & Maddison, 1992). 

The anatomical nomenclature follows Baumel et al. (1979, 1993), unless stated 

otherwise. 

GENERAL POSITION OF THE FAMILY PRESBYORNITHIDAE 

In order to determine the phylogenetic position of the Presbyornithidae within 

Aves, an extensive comparison was made with representatives of several nonpasseriform 

families. It is possible that this exercise represents the most comprehensive 

phylogenetic analysis of higher-level taxa based on skeletal characters utilizing 

cladistic methodology to date. Although the primary goal was to find the phylogenetic 

position of the Presbyornithidae, hypotheses regarding relations of all other taxa 

included were generated as well. Because this was not the prime purpose of the 

analysis, no attempt was made to fully resolve all parts of the phylogenetic tree. 

Admittedly, some polytomies in the strict consensus tree could possibly be resolved 

by a more extensive search for characters, but such a search was only conducted 

within the clade with which the Presbyornithidae was found to group, which formed 

the foundation for the second step of the phylogenetic analysis (see Methods). 

Selection of ingroup taxa 

As ingroup, a total of 41 nonpasserine families were included in the analysis, 

representing the orders Ciconiiformes, Anseriformes, Galliformes, Gruiformes and 

Charadriiformes (sensu Wetmore, 1960). These taxa were chosen to include first of 

all the families with which the Presbyornithidae have been suggested to bear 

close affinities (Phoenicopteridae, Anseriformes, Burhinidae and Recurvirostridae). 

Secondly, given the overall similarities of the Presbyornithidae and the Anseriformes,

436 


all taxa that, at some point in time, have been proposed as the sistergroup of the 

anseriformes were included as well (rest of Ciconiiformes, Galliformes). Thirdly, a 

number of families supposed to have close phylogenetic relationships with taxa 

already included, were added to the matrix (Opisthocomidae, Gruiformes, rest of 

Charadriiformes). The Pedionomidae, long placed with the Gruiformes (Wetmore, 

1960), was moved to the Charadriiformes by Olson & Steadman (1981). I concur 

with their classification, so that when discussing the order Charadriiformes below, 

the Pedionomidae are mentioned separately only for the sake of clarity. 

The anatomically highly peculiar and autapomorphic Turnicidae, traditionally 

placed with the Gruiformes, were originally included in the analysis. The Turnicidae 

combine skeletal morphologies resembling both galliforms and highly derived 

charadriiforms. At least one of these morphologies seems to have arisen by convergence. 

In the preliminary phylogenetic analyses, the Turnicidae flipped around 

wildly, causing serious instability of the tree topology. Sometimes, they came out 

basal to the Galliformes and sometimes well within the charadriiform clade. A final 

phylogenetic analysis of the Turnicidae obviously requires an expansion of the 

osteological information with other data sets, so it was decided to leave them out 

of further analyses. 

Outgroup 

The neognathous birds are generally assumed to be a monophyletic sister taxon 

to the palaeognathous birds (Cracraft, 1986; Kurochkin, 1995a, b). Whether the 

latter are monophyletic, paraphyletic or polyphyletic has been much disputed over 

the years (de Beer, 1956; Bock, 1963; Cracraft, 1974, 1986; Sibley & Ahlquist, 1981, 

1990; Olson, 1985; Bledsoe, 1988; Houde, 1988). In this analysis, the palaeognathous 

families Rheidae and Tinamidae serve as outgroup. Given the terrestrial adaptation 

and subsequent morphological specialization of the Rheidae, some features in the 

ingroup could not be observed in the Rheidae, and these are thus coded as not 

applicable for them. 

Character selection 

Many systematic works based on osteology were published during a period from 

1867 to c. 1920. This literature has been surveyed for characters useful to the present 

study. In addition, many new characters were found by extensive comparative work 

in museum collections. 

For several reasons only a minor part of all the morphological variation described 

in the literature was included in the analysis. The most important reason is that the 

postulated taxonomic distributions of characters could not be corroborated. That 

is, characters once claimed to be diagnostic of a family were often found to be 

highly variable within the same family. This is not to say that the systematists at 

the time were poor scientists, but in most cases errors occurred simply because 

investigators could not study all members of a family due to poor representation in 

museums. 

In the selection of characters for the study, the following three principles were 

applied:

ch. 1, state 1 




Figure 4. Cranium of Charadrius novaeseelandiae (NZNM 1403), Charadriidae, in ventral view. Modified 

after Strauch (1978). Character abbreviated to ‘ch.’ in this and all subsequent figures. 

(1) Great caution was taken in the coding of suspected character complexes, e.g. 

the palate type as defined by Huxley (1867). It is plausible, but unproven, that 

structures such as palate type are built up by several, co-evolving characters. To 

break up such a complex of covarying characters and treat them as independent 

in the analysis (as done in the case of the palaeognathous palate by Cracraft, 

1986:398), assigns the structure as a whole a higher weight than might be justified 

genetically. 

The opposite strategy, wherein complex structures are divided into a few, 

discrete character states, runs the risk of oversimplifying the morphological 

variation. In this work, a middle way was followed: only components of a 

character complex that did not obviously covary, were treated as independent 

characters. 

(2) Characters obviously correlated with the pneumatization of the skeleton were 

avoided. In practice, this relates only to large and highly pneumatic taxa such 

as Balaenicipitidae, Ciconiidae, Phoenicopteridae, Anhimidae, and Gruidae. 

The assumption is that convergent morphologies easily evolve as a response to 

an increasing pneumatization. Note that this principle was not followed in the 

second step of the phylogenetic analysis below, where the precise systematic 

position of the Presbyornithidae within a monophyletic order was studied. 

(3) No quantitative characters, or characters which states are defined by dividing a 

clearly continuous variation into discrete states, were included. 

Autapomorphic characters were not included in the matrix (Table 1). All characters 

were treated as unordered. 

Character descriptions 

1. Cranium: fonticulus occipitalis present in adulthood (Fig. 4) 

(0) absent; (1) present. 

Occipital fontanelles arise as a consequence of failure of fusion of the epiotic and 

supraoccipital bones. The physiological purpose of the occipital fontanelles is 

unknown and they have not been found in any Mesozoic bird. Among the studied 

taxa they occur in adults of Threskiornithidae, Phoenicopteridae, most Anseriformes 

(not in Anhimidae), Gruidae, Aramidae and several Charadriiformes (Seebohm,

438 


Table 1. Data matrix used in the first step of the analysis. 

Character no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 

Taxon 

Tinamidae 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 

Rheidae 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 

Ardeidae 0 0 0 0 0 1 1 2 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 1 0 0 0 0 2 0 0 1 0 

Balaenicipitidae 0 1 0 0 1 1 1 2 1 0 0 0 1 1 0 1 0 0 0 0 1 0 0 0 1 1 0 0 0 0 0 0 0 0 0 

Scopidae 0 1 0 0 0 1 1 2 1 0 0 0 1 1 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 0 2 0 0 1 0 

Ciconiidae 0 1 0 0 0 1 1 2 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 1 0 0 0 0 0 0 0 1 0 

Threskiornithidae 1 1 0 0 0 0 1 2 1 0 0 2 0 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 

Phoenicopteridae 1 1 0 1 0 1 1 2 1 0 0 0 0 0 0 1 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 

Anhimidae 0 1 1 0 0 1 0 2 0 0 0 0 0 0 0 1 1 1 1 0 1 0 1 0 0 1 0 0 0 0 0 0 0 0 0 

Anseranatidae 1 1 1 0 0 1 2 2 0 0 1 0 0 0 1 1 1 1 1 1 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 

Anatidae 1 1 1 0 1 1 2 2 0 0 1 0 0 0 1 1 1 1 1 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 

Megapodiidae 0 1 0 0 0 0 2 1 0 1 0 0 0 0 0 1 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 0 

Cracidae 0 1 0 0 0 1 2 1 0 0 0 0 0 0 0 1 0 1 0 0 1 0 0 0 0 0 0 0 1 1 2 0 1 0 0 

Phasianidae 0 1 0 0 0 1 2 1 0 1 0 0 0 0 0 1 0 1 0 0 1 0 0 0 0 0 0 0 1 1 2 0 1 0 0 

Opisthocomidae 0 1 0 0 1 1 1 1 1 0 0 0 0 0 0 1 0 1 0 0 1 0 0 0 0 1 0 0 0 0 2 0 0 0 1 

Mesitornithidae 0 1 0 0 0 1 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 ? 0 2 0 0 0 1 

Pedionomidae 0 0 0 0 2 1 0 1 1 1 0 2 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 

Gruidae 1 1 0 0 0 1 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 2 0 0 0 0 

Aramidae 1 1 0 0 0 1 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 2 0 0 1 0 

Psophiidae 0 1 0 0 0 0 1 1 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 2 0 0 0 0 

Rallidae 0 1 0 0 0 1 1 1 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 0 2 0 0 0 0 

Heliomithidae 0 1 0 0 1 1 1 1 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 1 0 1 2 0 0 0 0 

Rhynochetidae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 

Eurypygidae 0 1 0 0 0 1 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 1 0 1 0 

Cariamidae 0 1 0 0 0 1 1 1 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 1 0 0 0 1 2 0 0 0 0 

Otididae 0 1 0 0 0 0 1 1 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 1 1 0 0 0 0 2 1 0 0 0 

Jacanidae 0 1 0 0 1 0 0 1 1 1 0 2 0 0 0 1 0 0 0 0 1 0 0 1 0 0 0 1 0 0 0 0 0 0 0 

Rostratulidae 1 1 0 0 1 0 0 1 1 1 0 2 0 0 0 1 0 0 1 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Dromadidae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Haematopodidae 0 1 0 0 1 0 0 1 1 0 0 2 0 0 0 1 0 0 1 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Ibidorhynchidae 1 1 0 0 1 1 0 1 1 0 0 2 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Recurvirostridae 1 1 0 0 1 1 0 1 1 0 0 2 0 0 0 1 0 0 1 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Burhinidae 0 1 0 0 0 1 1 1 1 0 0 0 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 0 1 0 

Glareolidae 0 1 0 0 1 0 1 1 1 1 0 2 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 

Charadiidae 1 1 0 0 1 0 0 1 1 0 0 2 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Scolopacidae 1 1 0 0 1 0 0 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 

Thinocoridae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 0 

Chionidiidae 0 1 0 0 1 1 1 1 1 0 0 2 0 0 0 1 0 0 1 0 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 

Stercorariidae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 0 0 0 1 0 0 0 0 

Laridae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Rhynchopidae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 

Alcidae 0 1 0 0 1 0 1 1 1 0 0 2 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 

Presbyornithidae 1 1 1 1 0 1 2 1 0 0 1 0 0 0 1 1 0 1 1 1 1 1 1 0 1 1 1 0 0 0 1 0 0 1 0 

1888, 1895; Olson, 1979:167). The fontanelles are present embryologically in some 

charadriiforms, but are later fused, e.g. in Laridae (Seebohm, 1888:421). In some 

Charadriiformes, e.g. Chionis, they do not fuse until an advanced age. The Anatidae 

and several charadriiform families (cf. Strauch, 1978:299) are polymorphic in respect 

to the possession of occipital fontanelles in adulthood. The occipital fontanelles are 

present in most Anatidae, Recurvirostridae (not listed as polymorphic by Strauch, 

but fontanelles are lacking in some individuals of Cladorhynchus), Charadriidae, 

and Scolopacidae, which families were assigned state 1 in the analysis. In the 

Haematopodidae (fontanelles occur in e.g. H. leucopodus and H. ostralegus), Glareolidae, 

and Alcidae, the normal condition is to lack fontanelles and these taxa are thus 

given state 0. The Presbyornithidae possess occipital fontanelles. 

2. Cranium: processus postorbitalis 

(0) absent (or extremely small); (1) present. 

Most taxa studied have the postorbital process well-developed. It is absent, or almost 

absent, only in Tinamidae, Ardeidae and Pedionomidae.


Table 1. contd. 

36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

0 0 0 1 ? ? 0 0 ? 1 0 0 ? 0 0 0 0 0 0 0 0 0 0 0 ? 0 ? 0 1 0 ? 0 1 ? 0 1 

0 0 0 1 2 1 0 0 0 1 2 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 0 1 0 0 0 0 

0 1 0 1 2 1 0 0 ? 2 0 1 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 0 1 0 0 0 0 

0 0 0 1 1 1 0 0 1 2 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 1 0 0 0 0 

0 0 0 1 2 1 0 0 1 1 0 1 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 0 1 0 0 0 0 

0 0 0 1 1 1 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 1 0 0 0 0 

0 1 0 1 2 1 0 0 1 1 0 0 1 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 2 0 0 0 0 1 0 0 

0 1 1 1 2 1 0 0 1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 1 0 0 

0 0 1 1 2 1 0 0 1 1 0 0 1 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 1 0 0 

1 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 

1 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 

1 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 1 0 0 0 0 1 0 0 1 ? 1 0 

1 0 0 1 0 0 0 0 ? 1 0 0 0 1 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 1 0 

0 0 0 1 2 1 0 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 1 1 1 ? 1 0 1 0 0 0 0 0 

0 1 0 1 1 1 0 0 0 1 0 1 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 0 0 0 

0 1 0 1 1 1 0 0 0 2 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 

0 1 0 1 2 1 1 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 1 1 1 0 0 0 1 0 0 0 0 0 

0 1 0 1 1 1 1 0 0 0 1 1 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 

0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 0 1 0 0 0 0 0 

0 0 0 1 2 1 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 0 0 1 0 1 0 0 0 0 0 

0 0 0 1 1 1 1 0 0 2 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 

0 0 0 1 2 1 0 1 0 0 0 0 0 0 1 0 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 0 0 1 

0 0 0 1 2 1 1 1 1 1 0 0 0 1 0 1 1 0 1 0 0 0 1 0 1 1 1 0 0 0 1 0 0 0 0 0 

0 0 0 1 2 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 0 0 1 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 0 1 1 1 1 1 1 0 1 0 0 0 0 1 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 1 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 0 0 1 

0 0 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 0 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 1 

0 0 0 1 2 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 0 0 1 2 1 0 1 1 1 0 0 0 0 0 1 1 0 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 0 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 0 1 1 1 1 1 1 0 1 0 0 0 0 0 

0 1 0 1 2 1 0 1 1 1 0 0 0 0 0 1 0 0 1 1 0 1 0 1 1 1 1 0 1 0 1 1 0 0 0 0 

0 0 0 1 2 1 0 1 1 2 0 0 0 0 0 1 0 0 1 0 0 1 1 0 1 0 1 1 1 0 1 0 0 0 0 1 

0 1 1 1 2 1 0 0 1 1 0 0 1 0 0 0 0 0 1 1 0 0 0 0 1 1 1 0 2 0 1 0 0 1 0 0 

ch. 3, state 1 ch. 11, state 1 


Figure 5. Cranium of Polysticta stelleri (USNM 561199), Anatidae, in ventral view.

440 



Figure 6. Cranium of Pluvianus aegyptius (FM 93449), Glaerolidae, in lateral view. Modified after 

Strauch (1978). 

3. Cranium: ventral surface of processus postorbitalis distinctly excavated (Fig. 5) 

(0) no; (1) yes. 

A distinctly excavated ventral surface of the processus postorbitalis of the cranium is 

uniquely possessed by the Anhimidae, Anserantidae, Anatidae and Presbyornithidae. 

4. Cranium: frontale narrow and laterally rounded 

(0) no; (1) yes. 

In both the Phoenicopteridae and Presbyornithidae, the frontal region is narrow 

and the lateral margin smoothly rounded, a condition also present in a few rallids. 

The Rallidae are coded as 0 in the analysis given this is the most common condition 

found in the family. 

5. Cranium: os lacrimale (Fig. 8) 

(0) lacrimals present but not ossified to the nasofrontal region, or incompletely 

ossified with a suture clearly visible; (1) lacrimals completely ossified to the nasofrontal 

region; (2) lacrimals lost. 

The lacrimals are present in most nonpasserine birds but are absent in many 

Passeriformes (Cracraft, 1968:347). Among the taxa included herein they are lost 

in the Pedionomidae (Cracraft, 1968:338; Bock & McEvey, 1969:192). The lacrimals 

may, or may not, be fully fused to the frontals and nasals. Incompletely fused 

lacrimals are found in the Rheidae, most Ciconiiformes, Anhimidae, Anseranatidae, 

all Galliformes, most Gruiformes, Burhinidae and Presbyornithidae. The Tinamidae, 

Balaenicipitidae, Anatidae, Opisthocomidae, a few Gruiformes and almost all 

Charadriiformes, have them completely fused to the skull. Although Shufeldt (1901: 

299) states that some Threskiornithidae have the lacrimals fully co-ossified, this 

could not be confirmed by the present study. 

6. Cranium: ossa lacrimale and ectethmoidale fused or in touch (Fig. 6) 

(0) yes; (1) no. 

The lacrimal is not fused to the ectethmoid plate in all studied taxa except the 

Rheidae, Tinamidae, Threskiornithidae, Megapodiidae, some Gruiformes, and many 

Charadriiformes. The two bones are fused in many, but not all, Burhinidae and 

Recruvirostridae (unfused in Recurvirostra, contra Strauch 1978: table 1), while the 

opposite is the case with the Charadriidae. Following the most widespread condition, 

the Burhinidae and Recurvirostridae are assigned state 1 and Charadriidae state 0.


7. Cranium: basipterygoid articulation (Figs 4 and 5) 

(0) true, reptilian basipterygoid articulation; (1) absent; (2) rostropterygoid articulation. 

Weber (1993) distinguishes between two developmentally different, and non-homologous, 

basipterygoid articulations. The first is called a true basipterygoid articulation, 

homologous with that in reptiles (contra McDowell, 1978). Weber uses the 

term rostropterygoid articulation for the second morphology and postulates it to be 

a shared derived character of the Anseriformes and Galliformes. A significant 

problem with the analysis of Weber (1993), is that he did not include the aberrant 

anseriform family Anhimidae. In the Anhimidae, considered as the first branch on 

the anseriform tree by most systematists (e.g. Livezey, 1986), the basipterygoid 

articulation is very different from that in other anseriforms, approaching the 

morphology of the true, reptilian basipterygoid articulation (sensu Weber, 1993), as 

pointed out by Dzerzhinsky (1995:327). The basipterygoid articulation of the 

Anhimidae is in fact almost identical with that in, for example, the Scolopacidae; 

indeed, Hofer (1945) considered it a true basipterygoid articulation, non-homologous 

with that of other anseriforms. The Anhimidae further differ from all other Anseriformes 

in having the articulation in a mid-shaft position of the pterygoid, while 

the other anseriforms have it positioned at the anterior end of the bone (cf. 

Elzanowski, 1977:1304). The Presbyornithidae have a rostropterygoid articulation 

similar to that in Anatidae. 

Despite the uncertainties concerning homology exemplified above, and notwithstanding 

that basic structural differences exists in between the basipterygoid 

processes of anseriforms and galliforms (Olson & Feduccia, 1980b:4), I will here 

follow Weber and recognize three character states in the analysis of the basipterygoid 

articulation. 

Well-developed, reptilian basipterygoid processes articulating with the pterygoids 

occur in adults of all palaeognaths, a few Gruiformes and many Charadriiformes. 

In some taxa, e.g. the Balaeniceps, Ciconia, Otididae, Dromas, Chionis, Larus, and 

Rynchops, they are present in the young but suppressed later in life (Seebohm, 1888: 

430; Lowe, 1916a, b; Maillard, 1948; Elzanowski, 1977:1304; Strauch, 1978:295; 

Richard L. Zusi, pers. comm.). Some Phoenicopteridae have a rudimentary and 

non-functioning basipterygoid articulation (Gadow, 1877:384; Seebohm, 1889:97) 

coded as missing here in analogy with the coding of taxa in which the articulation 

is suppressed in the adults. A few species of the Otididae may retain the basipterygoid 

in adulthood but the entire family is here coded as lacking them. 

8. Facies: palatine articulation with parasphenoid (Figs 5 and 7) 

(0) palatines do not articulate with parasphenoid; (1) palatines articulate with 

parasphenoid but are not fused to each other; (2) palatines articulate with parasphenoid 

and are partly or fully fused to each other. 

The palatines are separated from the parasphenoid in all palaeognathous birds. In 

neognathous taxa in which they do articulate with the parasphenoid, the palatines 

may or may not be fused to each other. The latter morphology constitutes one of 

the conditions of the so-called desmognathous palate and is found in the Ciconiiformes 

and Anseriformes among the taxa studied. 

9. Facies: internal laminae of palatines obsolete (Fig. 7) 

(0) yes; (1) no. 

Well-developed internal palatinal laminae are present in all ingroup taxa except the

442 




Figure 7. Cranium of Ortalis vetula (USNM 322290), Cracidae, in ventral view. 

Anseriformes and Galliformes (cf. Huxley, 1868:295), but are absent in the Rheidae 

and Tinamidae, as well as in the Presbyornithidae. 

10. Facies: processus maxillopalatinus (Fig. 4) 

(0) well developed, broad and often inflated process (sometimes fused with os 

palatinum); (1) small and delicate processes, never fused to os palatinum. 

Huxley’s (1867) classification of the Class Aves rests primarily on the allocation of 

its members to either of four palatal morphologies defined by him. These structures 

should not be regarded as discrete characters, however, but are rather combinations 

of several characters. For example, having the maxillopalatine processes broad and 

well developed, and fused to the palatines, is part of the definition of the so-called 

desmognathous palatal type. The maxillopalatines are well-developed in most of 

the taxa studied, but are small and delicate in the Megapodiidae, Phasianidae, 

Pedionomidae, and a few Charadriiformes. 

11. Facies: position of processus jugale of os maxillare relative to maxillopalatinum (Figs 5 and 

7) 

(0) dorsal; (1) ventral. 

This character, first observed by Shufeldt (1901:300), is present in all taxa with 

spatulate bills, i.e. the Anseranatidae, Anatidae and Presbyornithidae. 

12. Cranial kinesis 

(0) prokinesis or amphikinesis; (1) ‘palaeognathous’ rhynchokinesis; (2) ‘neognathous’ 

rhynchokinesis. 

In an analysis of the kinesis of the avian skull, Zusi (1984) recognized three basic 

forms: prokinesis, amphikinesis and rhynchokinesis (of which the latter could be 

further subdivided). In neognathous birds, Zusi postulates prokinesis to be ancestral 

to amphikinesis, and amphikinesis to rhynchokinesis. On the other hand, prokinesis 

might evolve secondarily from rhynchokinesis (Zusi, 1984:30). The rhynchokinesis 

in palaeognathous birds, however, is suggested to have evolved independent of that 

in neognaths. In the definition of this character I have lumped all four rhynchokinetic 

stages by Zusi occurring in neognathous birds (double, distal, proximal and extensive 

rhynchokinesis) into one character state termed ‘neognathous’ rhynchokinesis, while




Figure 8. Cranium of Threskiornis aethiopica (USNM 613002), Threskiornithidae, in lateral view. 

the central rhynchokinesis present in ratites and some tinamous is called ‘palaeognathous’ 

rhynchokinesis. 

Zusi (1984:7ff ) further demonstrated that rhynchokinesis is a partial synonym of 

schizorhiny, as defined by Garrod (1873:33), and that the commonly accepted 

division of the Class Aves into holorhinal and schizorhinal birds is not applicable. 

Two polymorphic families were observed. Most species of the Tinamidae possess 

a ‘palaeognathous’ rhynchokinesis (a few have a ‘neognathous’ rhynchokinesis), and 

among the Threskiornithidae, the Plataleinae (spoon-bills) are prokinetic and the 

Treskiornithinae (ibises) ‘neognathous’ rhynchokinetic (ibises). The Tinamidae are 

assigned state 1 given that this is the most common condition in the family. Under 

the assumption that the Plataleinae are more derived than the Threskiornithinae, 

the Threskiornithidae are assigned state 2 in the analysis. 

13. Facies: ossified naso-ethmoidal septum 

(0) no; (1) yes. 

An ossified naso-ethmoidal septum is present in the Balaenicipitidae and Scopidae. 

Note that this character, as defined here, differs from the more commonly used 

‘nares pervious or impervious’. The latter refers to any septum, ossified or cartilageous 

(Gadow, 1893) and thus cannot be observed in the dry skull. 

14. Facies: rostrum with a long, distinct nasal groove (Fig. 8) 

(0) no; (1) yes. 

A long and distinct groove extending from the nasal opening to the tip of the bill 

is present in the Balaenicipitidae, Scopidae and Treskiornithidae. A similar groove 

is also present in several Pelecaniformes (Cottam, 1957; Cracraft, 1985:836). 

15. Facies: spatulate bill of ‘duck-like’ type 

(0) no; (1) yes. 

All the Anseriformes, except Anhimidae, and Presbyornithidae possess the typical, 

spatulate duck-bill, in which the enlarged tongue is accommodated in the upper 

jaw (Olson & Feduccia, 1980a) as opposed to other kinds of spatulate bills found in 

other ingroup taxa, e.g., Plataleinae (spoon-bills) and Eurynorhynchus pygmaeus (spoonbilled 

sandpiper). 

16. Quadratum: division of processus oticus into two heads 

(0) no; (1) yes. 

The articulation of the otic process of the quadrate to the neurocranium shows a 

considerable degree of variation (cf. Lowe, 1926). The character perhaps most 

widely used by systematists is whether the otic head of the quadrate articulates to 

the skull with a single facet as in palaeognaths, or with two facets as in the neognaths

444 


(e.g. Huxley, 1867:418; Cracraft, 1986:387). This character is not as clear-cut as 

might be thought, which already Lowe (1926) noted: “the single-headedness [of the 

palaeognaths] is not so basic a fact as some writers appears to have taken for 

granted” (p.157). Despite this observation, Lowe maintained the opinion that the 

ratites and Tinamidae share characters which set them apart from all other living 

birds (1926:158). 

17. Quadratum: processus mandibularis inflated posterior to the quadratojugal articulation 

(0) no; (1) yes. 

The processus mandibularis is inflated posterior to the quadratojugal articulation in 

the Anhimidae, Anseranatidae, and Anatidae, but not in the Presbyornithidae (Olson 

& Feduccia, 1980b:15). In other taxa which have the quadratojugal articulation 

positioned distinctly posterior to the mandibular articulation, e.g. some Phasianidae 

and Thinocoridae, this region may be positively expanded but never inflated. 

18. Mandibula: quadratal articulation 

(0) basically a three-condyle articulation, with cotyla medialis and cotyla lateralis 

separated by a shallow groove (a distinct posterior cotyla may or may not be present); 

(1) two-condyle articulation, with cotylae medialis and lateralis large and separated 

by an antero-posteriorly oriented crista intercotylaris. 

In most living birds the mandibula and quadrate articulate by a three-condyle 

articulation, where a groove of variable depth separates the lateral and medial 

condyles. This is true for all taxa examined except the Anseriformes, Galliformes, 

Opisthocomidae, and Presbyornithidae. Lebedinsky (1920:94) described this morphology 

as a two-condyle articulation where the lateral and medial condyles are 

separated by a “wulstartige Erhebung”. According to Thulborn (1984:216), the threecondyle 

articulation is primitive in extant birds, and the two-condyles articulation has 

arisen in some taxa when the posterior condyle have been secondarily reduced. 

19. Mandibula: large, dorsoventrally high, recurved retroarticular process 

(0) absent or vestigal; (1) present, well developed. 

When present, the retroarticular process basically serves as an area of insertion for 

M. depressor mandibulae (Vanden Berge, 1979:190). It seems likely that the 

development of this process is correlated with feeding adaptations and thus may tell us 

more about this than about relationships to other birds. Consequently, retroarticular 

processes are present in many evolutionary lineages of birds and show a considerable 

degree of morphological variation (cf. Lebedinsky, 1920:100ff.). 

Despite difficulties in establishing the homologies of this character, the retroarticular 

process has often been used in phylogenetic reconstruction. For example, 

Cracraft (1986, 1988) postulates a sistergroup relationship between the Anseriformes 

and Galliformes, based on, among other cranial characters, the shared possession 

of a “long, upwardly curving and strongly mediolaterally compressed retroarticular 

process”. Lebedinsky (1920), however, did not find any particular similarities between 

ducks and gallinaceous birds in his huge survey of mandibular morphologies in 

birds. Actually, based on the total morphological variation observed in the Class, 

he (1920:102) defined three different types of retroarticular processes: the ‘alciform’, 

the ‘anseriform’, and the ‘galliform’! Although I cannot find any generally valid 

similarities between the typical anseriform and typical galliform morphologies, it is 

obvious that the Anhimidae is closest to the latter. Furthermore, a few galliform 

genera have a retroarticular process very similar to that of the anatids. On the


other hand, I think Lebedinsky (1920:102) is correct when he states that the 

Phoenicopteridae have a process of the same design as have the Anatidae (i.e. his 

Anseriformes). 

During the process of describing and scoring this character, I found it very difficult 

to divide the taxa that possessed a retroarticular process into discrete states describing 

all the variations found. In order to take a very cautious approach I have recognized 

the condition typically found in the Phoenicopteridae, Anseranatidae, Anatidae, 

Rostratulidae, Haematopodidae, Recurvirostridae, Chionididae and Presbyornithidae, 

as homologous. Many Megapodiidae, and few Cracidae and Phasianidae, 

also possess a retroarticular process fitting the character description above. By letting 

the character state designation follow the majority of species in the family, the 

Megapodiidae will be assigned state 1, and the Cracidae and Phasianidae state 0. 

20. Mandibula: deep groove in the ventral surface of the anterior portion of the mandibular rami 


In the Anseranatidae and Anatidae, a deep groove runs roughly in an anteroposterior 

direction along the ventral surface of the mandibular rami. Such a groove 

is also present in the Presbyornithidae (Olson & Feduccia, 1980b:15). 

21. Mandibula: patterns of furrows in the bone caused by grooves present in the mandibular 

rhamphotheca 

(0) present, grooves extending to the tip of the mandible; (1) absent. 

The presence of a certain pattern of grooves in the rhamphotheca (both the premaxilla 

and mandibula) of living palaeognaths has been used to indicate monophyly of 

these groups (Parkes & Clark, 1966). Often, the rhamphothecal grooves are visible 

in the underlying bone (Olsen, 1985:98) and Houde (1988) showed they were present 

also in the volant palaeognath family Lithornithidae, known from the early Tertiary 

of North America and Europe. It seems, however, that this character is not as clearcut 

as may first have been thought. Actually, a condition very much resembling 

that found in modern palaeognaths is present in certain Pelecaniformes, especially 

Phalacrocoracidae. The character description above, based on the bony part of the 

mandible, has been phrased as to separate the palaeognaths (including Lithornithidae) 

from all neognaths. The Phalacrocoracidae differ from this description in that their 

mandibular grooves do not extent as far anteriorly as they do in the palaeognaths. 

Furthermore, the cormorants normally have the area between the two grooves much 

elevated with a bony process projecting aborally. 

22. Vertebrae thoracicae: all thoracic vertebrae heterocoelous 

(0) yes; (1) no. 

Most ingroup taxa have all vertebrae heterocoelous except a few in which some 

thoracic vertebrae are amphicoelous. In many Charadriiformes at least some of the 

thoracic vertebrae are amphicoelous, and in the Presbyornithidae, all of them are. 

It is uncertain if the amphicoelous vertebrae in certain charadriiforms is the result 

of the retention of a primitive character state (Martin, 1987), or of a secondary loss 

of heteroceolous vertebrae in parts of the vertebral spine. The distribution of 

heteroceolous vertebrae in Mesozoic birds suggests that this morphology has evolved 

at least twice in birds (Martin, 1987). The Rheidae have some of the thoracic 

vertebrae non-heterocoelous.

446 



Figure 9. Vertebrae thoracale of Anhima cornuta (NRM 600060), Anhimidae, in lateral view. 


Figure 10. Vertebra thoracale of Numenius arquata (NRM 886316), Scolopacidae, in lateral view. 

23. Vertebrae thoracicae: several thoracic vertebrae pleurocoelous, sometimes with pneumatization 

(Fig. 9) 

(0) no; (1) yes. 

Pleurocoelous, thoracic vertebrae, i.e. vertebrae with a deep lateral depression of 

the body, are consistently found only in the Anhimidae (and rarely in the Anatidae, 

wich thus is assigned state 0) among living birds. Other large and highly pneumatic 

birds such as the Balaenicipitidae, some Ciconiidae and Gruidae, often possess 

pneumatic foramina lateral on the vertebral corpus but they all lack the typical welldefined 

depression of the Anhimidae. The Presbyornithidae also have pleurocoelous 

thoracic vertebrae (most prominent in Telmabates, the largest member of the family, 

in which they are strikingly similar to those in the Anhimidae). 

24. Vertebrae thoracicae: area immediately dorsal to corpus (sometimes involving the whole corpus) 

conspicuously mediolaterally compressed (Fig. 10) 

(0) no; (1) yes. 

Many Charadriiformes, including the Pedionomidae, have the thoracic vertebrae 

mediolaterally very compressed in the region just dorsal of the corpus. The only 

charadriiform exceptions being some Stercorariidae which nevertheless have been 

assigned to state 1 following the most widespread condition. 

25. Vertebrae thoracicae: notarium present 

(0) yes; (1) no. 

In many birds, several thoracic vertebrae fuse to form a notarium (Storer, 1982). 

Among the taxa studied, a notarium is present in the Tinamidae, Threskiornithidae, 

Phoenicopteridae, most Anseriformes, Galliformes, Opisthocomidae, many gruiform 

families, and Jacanidae. Most Anatidae possess a notarium and this family is here 

assigned state 0.



Figure 11. Pelvis of Ortalis vetula (USNM 322290), Cracidae, in dorsal view. 

26. Pelvis: distinct, large pneumatic foramen present in the area between the prezygapophysis and 

diapophysis of the first synsacro-thoracic vertebrae 

(0) yes; (1) no. 

Several of the families studied are polymorphic in this character although an 

overwhelming majority of the species and individuals included possess the foramen, 

suggesting it has been lost in the taxa where it is lacking. In the Ciconiidae and 

Opisthocomidae the foramen is missing in only a few individuals and these families 

are thus assigned state 1 in the analysis. 

27. Pelvis: corpus of the first synsacro-thoracic vertebra 

(0) about equally compressed mediolaterally, as are the corpi of the following 

vertebrae; (1) first synsacro-thoracic vertebra considerably more mediolaterally 

compressed. 

A synsacrum with the first synsacro-thoracic vertebra significantly more mediolaterally 

compressed than in the following vertebrae, is a condition present in the 

Anseranatidae, Anatidae and Presbyornithidae among the taxa studied. 

28. Pelvis: mediolateral compression of the corpi of the synsacro-thoracic and synsacro-lumbar 

vertebrae 

(0) not very mediolaterally compressed; (1) two or more vertebrae conspicuously 

mediolaterally compressed. 

To have several anterior vertebrae of the synsacrum conspicuously mediolaterally 

compressed is a widespread condition within the Charadriiformes. This morphology 

is considered non-homologous to that described in character no. 27. 

29. Pelvis: canalis iliosynsacralis wide with the posterior opening large and round (Fig. 11) 

(0) yes; (1) no. 

A large canalis iliosynsacralis with the posterior opening wide is present only in the 

Tinamidae, Megapodiidae, Cracidae, and Phasianidae, while most other taxa

448 



Figure 12. Pelvis of Phasianus colchicus, Phasianidae, in lateral view. Modified after Holman (1964). 


Figure 13. Pelvis of Metopidius indicus (UMMZ 214551), Jacanidae, in lateral view. Modified after 

Strauch (1978). 

studied lack this canal. In those few that possess a canalis iliosynsacralis, e.g. the 

Rhynochetidae, the canal is neither large nor round, but mediolaterally very narrow. 

30. Pelvis: fenestra ischiopubica (Figs 12 and 13) 

(0) broad, pubis approaching ischium only immediately caudal of foramen obturatum 

and at processus terminalis; (1) narrow, pubis often partly fused to ischium. 

This is a rather clear-cut character, easy to score for most taxa. The following 

polymorphic taxa were assigned state 0 given that this was the most widely distributed 

state: Tinamidae (fenestra ischiopublica narrow in Rhynchotus, Nothura and Nothoprocta), 

Mesitornithidae (narrow in Monias), and Aramidae (narrow in but a few individuals 

of Aramus guarauna). 

31. Pelvis: recessus iliacus 

(0) recessus iliacus lacking; (1) recessus iliacus moderately invaginated; (2) recessus 

iliacus very deeply invaginated. 

Many ingroup taxa have a renal depression which may end caudally in a more or 

less well developed recessus iliacus. A true recessus iliacus can be confused with 

depressions due to the pneumatization of this region. I consider this to be the case 

in the Balaenicipitidae, Threskiornithidae, Phoenicopteridae, Anhimidae, Anseranatidae 

and Presbyornithidae, in which individuals with poor pneumatization 

in this area typically lack a recessus iliacus (e.g. Balaeniceps rex USNM 344963, 

Phoenicopterus chilensis USNM 347008, Phoeniconias minor USNM 488729). Most Ciconiidae 

possess state 0 (state 1 is present in Ciconia) and the family is assigned to 

this state in the analysis, as are the Rostratulidae (despite Nycticryphes possessing state 

1). Following the character state in the majority of the included species, the



Figure 14. Sternum of Tetrao urogallus, Phasianidae, in lateral view. Modified after Selstam & Selstam 

(1973). 

Megapodiidae are assigned state 1, although state 2 occurs in Alectura. A recessus 

iliacus is absent in the Rheidae and Tinamidae. 

32. Pelvis: a distinct, deep pneumatic depression present medio-posteriorly on ilium 

(0) no; (1) yes. 

In the Eurypygidae and Otididae, the posterior part of the ilium has a rather 

distinct pneumatic foramen visible in distal view. Also in the Scopidae this area is 

pneumatized, but here by numerous small foramina scattered along the medial part 

of posterior ilium almost all the way back to processus terminalis ilii. That morphology 

is thus considered non-homologous to that of the Eurypygidae and Otididae. 

33. Pelvis: distal end of processus terminalis ilii flat and triangular in distal view 

(0) no; (1) yes. 

This morphology is present in the Cracidae and Phasianidae. 

34. Sternum: left sulcus articularis coracoideus overlaps the right sulcus 

(0) no; (1) yes. 

Crossed coracoidal sulci occur in all ‘traditional’ Ciconiiformes (except Balaenicipitidae), 

Aramidae, Eurypygidae, Burhinidae and Presbyornithidae. It is also 

present in many Mesozoic birds, e.g. Ichthyornis and Ambiortus, as well as in the 

Lithornithidae. In all fossil and Recent birds known to me, it is always the left sulcus 

that overlaps the right, a pattern unlikely to have arisen by chance. 

35. Sternum: carina poorly developed with apex carinae situated extremely far caudally 

(0) no; (1) yes. 

This morphology occurs in the Opisthocomidae and Mesitornithidae. 

36. Sternum: processus craniolateralis very well developed, spina interna a broad cranial continuation 

of pars cardiaca, roofing the coracoidal sulci, spinae externa and interna fused (Fig. 14) 

(0) no; (1) yes. 

This morphology is possessed by the Galliformes and Mesitornithidae. A superficially 

similar state occurs in the Tinamidae but only involves the spina interna, however,

450 








Figure 15. Left coracoids of (from left) Colinus virgianus, Phasianidae, and Anseranas semipalmata (NRM 

926253), Anseranatidae, in dorsal view. The former illustration modified after Holman (1964). 

and is thus considered non-homologous (the spina externa is not developed at all 

in Tinamidae). 

37. Coracoid: small foramen N. supracoracoidei which penetrates the shaft (Fig. 15) 


A foramen N. supracoracoidei occurs in many ingroup taxa. Although a few species 

of the Glareolidae, Charadriidae and Alcidae possess this foramen, most species do 

not and these families are thus assigned state 0 in the analysis. The foramen N. 

supracoradoidus occurs in most Anhimidae, but may be absent in some individuals 

of Chauna, and the family is thus coded as state 1. The opening present on the 

medial part of shaft in some Threskiornithide and Otididae is obviously not 

homologous to foramen N. supracoracoidei but is merely results from an ossification 

of a tendon extending from the procoracoid process distally along the medial side 

of shaft. 

38. Coracoid: striae of muscle scars present on facies dorsalis of sternal end (Fig. 15) 

(0) no; (1) yes. 

Raised diagonally, striae of muscle scars on the dorsal surface of the coracoid are 

present in the Anseranatidae, Anatidae and Presbyornithidae. Similar striae are 

found in the Threskiornithidae, but here the striae are less developed and do not 

extend as far proximally on the shaft, making the homology uncertain. It is here 

assumed they are non-homologous. 

39. Coracoid: coracoid pneumatized by a foramen positioned on facies dorsalis immediately below 

cotyla scapularis 

(0) yes; (1) no. 

A distinct, dorsal pneumatic foramen penetrates the coracoidal shaft of the coracoid, 

just distal to the scapular articulation, in the Tinamidae and Opisthocomidae. The 

only Mesozoic birds in which a similar pneumatic foramen occur are the



Figure 16. Furcula, coracoid and sternum of Podica senegalensis, Heliornithidae, in ventral view. Modified 

after Beddard (1890). 

Enantiornithes (cf. Walker, 1981:fig. 2, Chiappe & Calvo, 1994:232), but the 

homology of this condition with that of Tinamidae and Opisthocomidae is highly 

questionable. 

40. Coracoid: cotyla scapularis (Fig. 15) 

(0) a true cotyla absent; (1) cotyla present, shallow; (2) cotyla deep and cup-formed. 

The design of the scapular cotyla has been divided into three states. The Rheidae 

are unique among the taxa studied in having the scapula fused to the coracoid. 

41. Coracoid: processus procoracoideus very short and blunt (Fig. 15) 

(0) yes; (1) no. 

The procoracoid process is very short and blunt in the Tinamidae, Galliformes and 

Mesitornithidae. 

42. Coracoid: processus procoracoideus fused with, or broadly bordering on furcula (Fig. 16) 

(0) no; (1) yes. 

Although most pronounced in the Opisthocomidae and Cariamidae, a processus 

procoracoideus fused with, or broadly bordering on the furcula, is a condition 

present also in the Psophiidae, Rallidae, Heliornithidae, Rynchopidae and Jacanidae. 

At a first glance, it may seem that this morphology is present also in the Balaenicipitidae 

and several Charadriiformes, but in these taxa the processus procoracoideus 

is directed more towards processus acrocoracoideus of the coracoid (to 

which it is normally united by a ligament).

452 



Figure 17. Left coracoid of Pedionomus torquatus (NMV W6084), Pedionomidae, in ventral view. Modified 

after Bock & McEvey (1969). 







Figure 18. Furculae of (from top) Megapodius freycinet (USNM 556999), Megapodiidae, and Dendrocygna 

bicolor (USNM 488131), Anatidae, and in lateral (left) and cranial (right) views. 

43. Coracoid: processus acrocoracoideus protruding far medially where the mediocaudal part forms 

a caudally projected hook in ventral view. Facies articularis clavicularis generally deeply undercut 

(Fig. 17) 

(0) no; (1) yes. 

This morphology occurs in all traditional Charadriiformes, Pedionomidae and 

Otididae. Other taxa, like the Psophiidae and Rhynochetidae, may have a hookshaped 

medial margin too, but in these the acrocoracoid does not protrude very far 

medially and does not conform with the description above of the derived state.



Figure 19. Cranial end of right scapula of Phoenicopterus ruber (NRM 926254), Phoenicopteridae, in 

lateral view. 

44. Furcula: general morphology (Fig. 18) 

(0) clavicles fused, weakly developed, often dorsoventrally very thin near point of 

fusion, furcula straight or slightly curved; (1) clavicles fused, generally ovoid or 

rounded near point of fusion, furcula robust and distinctly curved. 

Two general types of furcula occur among the ingroup taxa. A robust and curved 

furcula is the most wide spread morphology, present in the Ciconiiformes, Anseriformes, 

Charadriiformes and Presbyornithidae. The second type is very weakly 

developed furcula which is much less curved, almost straight, and often very thin 

near the point of fusion. This type of furcula is present in the Tinamidae, Ardeidae, 

Galliformes, and all traditional Gruiformes (i.e. excluding Pedionomidae). Juvenile 

specimens can often provide additional information in taxa in which the furcula has 

fused to the sternum and thus cannot readily be compared in the adult state. In the 

Gruidae, for example, the clavicles seem rather weakly developed in a juvenile Grus 

antigone (USNM 557944) and this family has tentatively been assigned to state 0. 

This is also true for the Opisthocomidae (USNM 223903). No juvenile of Balaeniciptidae 

was available, however, so no assignment of this taxon was possible. 

In the Rheidae and Mesitornithidae the clavicles are absent or greatly reduced, and 

thus not fused (Glenny & Friedmann, 1954). 

45. Furcula: processus acromialis (Fig. 19) 

(0) broadly rounded with facies articularis acrocoracoidea poorly developed; (1) 

pointed; (2) pointed with facies articularis a distinct, flat articulation. 

The processus acromialis of the furcula is broadly rounded in the Tinamidae, 

Galliformes, Opisthocomidae and many Gruiformes, whereas it is pointed in most 

other taxa examined. Exceptions are the Balaenicipitidae, Scopidae, Aramidae, 

Cariamidae and Alcidae, which have a distinct, flat articulation (acrocoracoid flange 

of Cottam, 1957). The condition of the Opisthocomidae was determined from 

juvenile specimens with the furcula not yet fused to the coracoid. 

46. Furcula: apophysis furculae (hypocleideum) (Fig. 18) 

(0) absent, or a small to moderately large process, often projected ventrally; (1) very 

large, bladelike, caudoventrally, projecting process; (2) long spikelike, cranially 

projecting process. 

The Galliformes and Heliornithidae have a large, bladelike hypocleideum that 

projects caudoventrally. A long, cranially projecting process is only found in the 

Ardeidae and a few Rallidae (very well-developed in a few species of Rallus). Most 

Rallidae conform to state 0, however. 

47. Furcula: apophysis furculae abutting with, or fused to sternum (Fig. 16) 

(0) no; (1) fused to or abutting with apex carinae. 

In some avian taxa the furcula is fused to, or in contact with, the sternum. When

454 






Figure 20. Left humeri of (from left) Burhinus magnirostris (UMMZ 214183), Burhinidae, and Catoptrophorus 

semipalmatus (UMMZ 156426), Scolopacidae, in caudal view. Modified after Strauch (1978). 

fused, the most common morphology among the taxa studied is to have the furcula 

abutting with, or fused to, the apex carinae of the sternum. This is the condition 

found in the Balaenicipitidae, Ciconiidae, Gruidae, and Heliornithidae. In the 

Opisthocomidae the hypocleideum is fused to the manubrium, a condition assumed 

to be non-homologous to the present character. 

48. Scapula: acromion pointed and protruding far more cranially than tuberculum coracoideum, 

facies articularis clavicularis distinctly concave (Fig. 19) 

(0) no; (1) yes. 

A pointed and cranially proturding processus acromion is found only in the 

Phoenicopteridae, Anatidae and Presbyornithidae among the taxa examined. 

49. Scapula: caudal part of shaft distinctly angled ventrally 

(0) no; (1) yes. 

A distinctly angled shaft is present in the Mesitornithidae, Rallidae and Jacanidae. 

The scapula is straight and slender in all sufficiently known Mesozoic birds. 

50. Scapula: caudal part of shaft distinctly broadened 

(0) no; (1) yes. 

A very broad caudal part of scapula is consistently present in the Mesitornithidae 

and Otididae. 

Although a few Cracidae and Cariamidae also possess this morphology, most do 

not, so these families are assigned state 0. 

51. Humerus: caput humeri undercut and fossa pneumotricipitalis dorsalis well developed (Fig. 

20) 

(0) no; (1) yes.





Figure 21. Proximal left humerus of Megapodius freycinet (USNM 556999), Megapodiidae, in caudal 

view. 

A humerus with an undercut caput humeri and a well-developed fossa pneumotricipitalis 

is present in most Charadriiformes (the only exceptions are the Dromadidae 

and Stercorariidae). 

52. Humerus: a slightly elevated muscle scar present in incisura capitis 

(0) no; (1) yes. 

In most taxa studied the groove between caput humeri and tuberculum ventrale is 

deep and smooth. In some Charadriiformes, a well-defined muscle scar occurs in 

the incisura capitis. 

53. Humerus: crista incisurae capitis present (Fig. 21) 

(0) no; (1) yes. 

Among the taxa studied, the caput humeri and tuberculum ventrale are connected 

by a bony ridge in the Galliformes. 

54. Humerus: tuberculum ventrale (Figs 20 and 21) 

(0) poorly developed; (1) well-developed. 

A well-developed ventral tuberculum on the proximal end of humerus is present in 

all taxa studied except the Tinamidae, Rheidae and Galliformes. 

55. Humerus: anconal surface of crista deltoidea (Figs 20 and 21) 

(0) convex; (1) concave. 

A convex anconal surface of the deltoid crest seems to be the most widespread 

condition in living birds. The Ciconiiformes, Anseriformes, Opisthocomidae, most 

Gruiformes, many Charadriiformes and Presbyornithidae, however, have the surface 

concave (cf. Zusi & Jehl, 1970:767; Strauch, 1976; Strauch, 1978:312). The Anatidae 

and Jacanidae are polymorphic regarding this character. However, the most widespread 

condition in Anatidae is to have the anconal surface concave, while the 

opposite situation prevails in the Jacanidae (contra Strauch, 1978:Table 1, the surface 

is rather concave in several individuals of Jacana). The Anatidae are assigned state 

1 and the Jacanidae state 0 in the analysis. Note that Strauch’s (1978:Table 1) listing 

of Calidris canutus as having a concave anconal surface, is probably a lapsus since it 

is clearly convex in all 11 specimens I studied.

456 




Figure 22. Proximal left humerus of Numenius arquata (NRM 886316), Scolopacidae, in cranial view. 

56. Humerus: crista deltoidea strongly deflected medially 

(0) no; (1) yes, apex situated almost at the distal end of crista. 

The Opisthocomidae and Psophiidae possess a strongly deflected deltoid crest which 

has the apex situated very far distally. Although the deltoid crest is very deflected 

in the Rhynochetidae, too, the apex is somewhat inflated and positioned more 

proximally in that taxon, which is here considered a uniquely derived condition, 

non-homologous with the present character. 

57. Humerus: impressio coracobrachialis deep and triangular (Fig. 22) 

(0) no; (1) yes. 

A deep, triangular impression for the insertion of M. coracobrachialis cranialis 

situated on the cranial surface of the proximal end of the humerus occurs in most 

Charadriiformes (Fürbringer, 1888), except Burhinidae and Pedionomidae. The 

Rostratulidae are polymorphic for this character (the impression is absent in all 

individuals of Rostratula examined, but present in several specimens of Nycticryphes). 

Neither morphology predominates among the species examined, so this family was 

assigned tentatively state 0 in the analysis. 

58. Humerus: canal for N. coracobrachialis cranialis pronounced and partly closed (Fig. 22) 

(0) no; (1) yes. 

A partly closed canal for N. coracobrachialis cranialis is only known to occur in 

most, but not all, Charadriiformes (including Pedionomidae) (Ballmann & Adrover, 

1970:59; Ballmann, 1979; Olson & Steadman, 1981:14). The canal is lacking in 

most Haematopodidae (except for a few individuals of Haematopus leucopodus USNM 

18547 and 488236), and Laridae (although present in Pagophila and some individuals 

of Sterna maxima), which are thus assigned state 0 in the analysis. 

59. Humerus: processus ectepicondylaris (Fig. 20) 

(0) absent or poorly developed; (1) well developed, extending as a ridge distally. 

The Pedionomidae and most Charadriiformes (exceptions are Burhinidae and most 

species of Jacanidae and Alcidae), possess this process. Processus epicondylaris occurs 

in a few species of the Alcidae and Jacanidae (rather well-developed but not pointed 

in Hydrophasianus and Irediparra), but following the majority of species, these families 

are assigned state 0.



Figure 23. Distal left humeri of (from left) Megapodius freycinet (USNM 556999), Megapodiidae, and 

Dendrocygna bicolor (USNM 488131), Anatidae, in dorsal view. 



Figure 24. Right ulnae of (from left) Anseranas semipalmata (NRM 926253), Anseranatidae, and Megapodius 

freycinet (USNM 556999), Megapodiidae, in ventral view. 

60. Humerus: scar for M. flexor carpi ulnaris on processus flexorius (Fig. 23) 

(0) one large scar; (1) two scars, normally of equal size and depth. 

A deep scar can be observed where the tendinous head of M. flexor carpi ulnaris 

attaches on processus flexorius. In the Tinamidae, Galliformes, Heliornithidae, 

Rhynochetidae, Eurypygidae, and Cariamidae, only a single scar can be observed, 

whereas it is divided into two parts of about equal size in all other ingroup taxa. 

No scar can be observed in the Rheidae, probably due to the marked reduction of 

the wing muscles in this taxon. 

61. Ulna: shaft compressed laterally with ventral side flattened (but articulating ends not compressed) 

(Fig. 24) 

(0) yes; (1) no. 

A laterally compressed ulnar shaft with the ventral side flattened is present in the 

two outgroup families, Rheidae and Tinamidae. It is also found in the Galliformes,

458 




Figure 25. Right ulnae of (from left) Megapodius freycenit (USNM 556999), Megapodiidae, and Numenius 

arquata (NRM 886316), Scolopacidae, in distal view. 


Figure 26. Left ulnare of Numenius arquata (NRM 886316), Scolopacidae, in dorsal view. 

Opisthocomidae, Mesitornithidae, Psophiidae, Heliornithidae, and Cariamidae. All 

other ingroup taxa have the cross-section of the ulnar shaft more or less circular. 

Despite the rather triangular cross-section of shaft, the Anhimidae do not have the 

ventral side flattened as in the taxa listed above and are here referred to state 0. 

All genera of Rallidae except Notornis have the ulnar shaft laterally compressed and 

the family is assigned state 0. Although generally strongly compressed too, the ulnar 

morphology of the Alcidae differs from the rest in that the compression involves 

not only the shaft but the articulating ends as well. This condition is considered 

non-homologous with the present character. 

62. Ulna: condylus ventralis low and ventrally truncated making sulcus intercondylaris wide and 

shallow (Fig. 25) 

(0) yes; (1) no. 

A ventrally low condylus ventralis is found in the Tinamidae, Megapodiidae, 

Cracidae, most Phasianidae (not in Lagopus or Francolinus), Opisthocomidae, Mesitornithidae, 

Psophiidae, Heliornithidae, Rhynochetidae, Eurypygidae, and Cariamidae. 

63. Carpi ulnare: insertion of lig. humerocarpale shaped as a distinctly, cranio-caudally compressed 

tuberculum, with a prominent groove on the ventral side of crus longum for the tendons of M. flexor 

digitorum superficialis and profundus. The area between this tuberculum and the ulnar articulation 

clearly hollow-shaped (Fig. 26) 

(0) no tuberculum; (1) yes. 

The lig. humerocarpale inserting on a prominent tuberculum at the proximal side 

of the os carpi ulnare occurs in most Charadriiformes (except Jacanidae, Burhinidae 

and Rynchopidae), as well as in the Heliornithidae. Due to lack of comparative 

specimens the condition in the Pedionomidae is unknown.




Figure 27. Proximal end of right carpometacarpus of (from left) Megapodius freycinet (USNM 556999), 

Megapodiidae, and Numenius arquata (NRM 886316), Scolopacidae, in caudal view. 


Figure 28. Right carpometacarpi of (from left) Grus canadensis (Gruidae), Tetrax tetrax (Otididae), 

Opisthocomus hoatzin (Opisthocomidae), Cariama cristata (Cariamidae), in ventral view. Modified after 

Olson (1985). 

64. Carpometacarpus: distal extension of trochlea dorsalis (Fig. 27) 

(0) falling considerably short of trochlea ventralis; (1) falling only slightly short of 

trochlea ventralis; (2) equals or exceeds the distal extension of trochlea ventralis. 

The dorsal trochlea of the proximal carpometacarpus falls considerably short in 

distal extent of the ventral trochlea in the Tinamidae, Galliformes, Opisthocomidae, 

Mesitornithidae, Psophiidae, Rallidae, Heliornithidae, Cariamidae, Jacanidae, and 

Chionididae. In most other taxa, the dorsal trochlea is only slightly shorter that the 

ventral. In the Anhimidae and Presbyornithidae, however, the distal extension of 

the dorsal trochlea equals that of the ventral, or extends even more distally. 

65. Carpometarcarpus: area of proximal fusion of metacarpi II and III (Fig. 28) 

(0) metacarpus III not very broad, or strongly deflected ventrally; (1) base of 

metacarpus III very broad and strongly deflected ventrally, set off from mid-shaft 

of metacarpus II. 

Although several ingroup taxa have metacarpus III more or less ventrally deflected, 

the combination of having its proximal base very broad and set off from the midshaft 

is a uniquely derived condition. Olson (1985:143) described this morphology 

in the Opisthocomidae and Cariamidae, and the Psophiidae are here added to these 

taxa.

460 




Figure 29. Proximal end of right tibiotarsi of (from left) Threskiornis aethiopica (USNM 613002), 

Threskiornithidae, and Dendrocygna bicolor (USNM 488131), Anatidae, in medial view. 


Figure 30. Proximal end of left tibiotarsi of (from left) Melanitta nigra, Anatidae, and Ardea herodias, 

Ardeidae, in cranial view. Modified after Stolpe (1932) and Shufeldt (1900). 

66. Tibiotarsus: shape of crista cnemialis cranialis (Fig. 29) 

(0) truncated cranially and extending about equally far proximally as crista patellaris; 

(1) cranioproximally well developed. 

Having the cranial cnemial crest cranioproximally well-developed is the most 

widespread condition among the ingroup taxa. A cranially truncated crest is present 

in the Tinamidae, Ardeidae, Balaenicipitidae, Ciconiidae, most Threskiornithidae 

(not Plegadis), Anhimidae, Megapodiidae, Cracidae, most Phasianidae (not Meleagris 

and Agriocharis), and Opisthocomidae. In the Rheidae the cranial cnemial crest is 

also truncated proximally, but it is much thicker and projects further cranially, a 

morphology here considered as non-homologous with the present character. 

67. Tibiotarsus: caudal part of facies articularis medialis (Fig. 30) 

(0) well developed with the incisura distinct; (1) poorly developed which makes the 

incisura on the caudal margin of head very shallow. 

In proximal view, the caudal margin of facies articularis medialis and lateralis is 

deeply notched in most birds. In several Ciconiiformes (Ardeidae, Balaenicipitidae, 

Scopidae and Ciconiidae) this notch is very shallow or absent, however. This is also 

true of many Threskiornithidae (but is rather well-developed in Threskiornis and 

Plegadis).




Figure 31. Distal end of right tibiotarsi of (from left) Treskiornis aethiopica (USNM 613002), Threskiornithidae, 

and Dendrocygna bicolar (USNM 488131), Anatidae, in cranial view. 

68. Tibiotarsus: pons supratendineus (Fig. 31) 

(0) ossified; (1) non-ossified. 

An ossified supratendinal bridge is absent in the Rheidae and Opisthocomidae. 

Although an incompletely ossified supratendinal bridge also occurs in some individuals 

of Ardeidae, Haematopodidae and Alcidae, these families are assigned 

state 0 in the analysis. 

69. Tibiotarsus: distal opening of canalis extensorius positioned equally far from either of the 

condyles, or closer to the lateral condyle (Fig. 31) 

(0) no; (1) yes. 

Among the birds possessing an ossified supratendinal bridge, the position of the 

distal opening of canalis extensorius varies. In most taxa it is situated much closer 

to the medial condyle than it is to the lateral. In the Anhimidae, Anseranatidae, 

Anatidae, Heliornithidae, and Presbyornithidae, the opening is situated approximately 

at equal distance from the condyles. The Rallidae are polymorphic in 

that although most rallids have the distal opening of canalis extensorius closest to 

the medial condyle, Notornis has it situated at an equal distance from the condyles. 

70. Tarsometatarsus: proxiomedial part of shaft broad relative to mid-shaft, ventral margin very 

sharp (Fig. 32) 

(0) no; (1) yes. 

The proxiomedial margin of the tarsometatarsal shaft is very sharp and broadened 

in the Megapodiidae, most Cracidae (less so in Crax), Opisthocomidae and Mesitornithidae. 

71. Tarsometatarsus: hallux 

(0) present; (1) absent. 

A hallux is lacking in the Rheidae, Otididae, and many Charadriiformes. The 

Recurvirostridae, Glareolidae, Charadriidae and Scolopacidae are polymorphic in 

respect to this character. In all of the last families, except the Charadriidae, the 

most widespread condition is to possess a hallux, so these taxa are assigned state 0. 

The Charadriidae normally lack the hallux and are thus coded as 1.

462 



Figure 32. Left tarsometatarsus of Megapodius freycinet (USNM 556999), Megapodiidae, in plantar view. 

Results 

The phylogenetic analysis generated 900 trees, each 235 steps long, consistency 

index (c.i.) 0.34, retention index (r.i.) 0.69. Most differences in the branching orders 

in these trees occurred within the clade of families traditionally referred to the 

Charadriiformes (including the Pedionomidae). In order to reduce the size of the 

data matrix, the Charadriiformes were replaced by a new taxon constructed from 

the character states of the outgroup node of the charadriiform clade. In addition, 

the Burhinidae, postulated to be the most basal member of the Charadriiformes by 

the first analysis, were retained in the matrix. By this action, the size of the matrix 

was reduced to 28 taxa from the original 43. 

In the analysis of this new, less inclusive, data matrix, 36 equally parsimonious 

trees were obtained (180 steps, c.i. 0.41, r.i. 0.63). The removal of 16 charadriiform 

families proved not to affect the topology of the trees outside the charadriiform 

clade (compare Figs 33 and 34). The large number of trees obtained in the first 

analysis obviously reflects the high degree of homoplasy in the data matrix, of which 

a significant amount was removed by the exclusion of the 16 charadriiform families. 

The Presbyornithidae grouped together with the Anseriformes (families Anhimidae, 

Anseranatidae and Anatidae) in all 36 trees. In the strict consensus tree (Fig. 

35), the Anseranatidae constitute the sister to the Presbyornithidae and Anatidae, 

and these three together form the sisterclade of the Anhimidae. There is thus no 

doubt that the Presbyornithidae are true anseriform birds. Given the obvious ducklike 

cranial morphology of the Presbyornithidae, it might be suspected that the 

placement of the family together with Anseranatidae and Anatidae is simply due to 

their many cranial similarities. This is not entirely true, however. The clade consisting 

of Ansernatidae, Presbyornithidae and Anatidae was also maintained (with a 0.76 

Parsimony Jackknifing support of the basal node) when all cranial, quadratal and 

mandibular characters were excluded from the analysis. 

As is evident from Figure 35, the strict consensus tree is rather poorly resolved.


(a) 

Rheidae 

Tinamidae 

Megapodiidae 

Cracidae 

Phasianidae 

Mesitornithidae 

Eurypygidae 

Rhynochetidae 

Heliornithidae 

Cariamidae 

Opisthocomidae 

Psophiidae 

Rallidae 

Otididae 

Gruidae 

Aramidae 

Burhinidae 

Laridae 

Rynchopidae 

Chionididae 

Glareolidae 

Alcidae 

Thinocoridae 

Scolopacidae 

Jacanidae 

Rostratulidae 

Pedionomidae 

Haematopodidae 

Charadriidae 

Recurvirostridae 

Ibidorhynchidae 

Stercorariidae 

Dromadidae 

Phoenicopteridae 

Anhimidae 

Anseranatidae 

Anatidae 

Presbyornithidae 

Ardeidae 

Scopidae 

Balaenicipitidae 

Ciconiidae 

Threskiornithidae 

Figure 33. Strict consensus tree based on 900 trees (235 steps, c.i. 0.34, r.i. 0.69). The clade at node 

(a) corresponds to the 17 families normally referred to the order Charadriiformes (sensu Wetmore, 

1960, but with the inclusion of the Pedionomidae, following Olson & Steadman, 1981). 

Furthermore, in a Parsimony Jackknifing analysis only a few of the branches scored 

0.70 or higher. Some of the most important and well supported results that can be 

derived from the tree are:

464 


Rheidae 

Tinamidae 

Megapodiidae 

Cracidae 

Phasianidae 


Eurypygidae 

Rhynochetidae 


Cariamidae 


Psophiidae 

Rallidae 

Otididae 

Gruidae 

Aramidae 

Burhinidae 

Charadriiformes 


Anhimidae 

Anseranatidae 

Anatidae 


Ardeidae 

Scopidae 


Ciconiidae 


Figure 34. Strict consensus tree based on 36 trees (180 steps, c.i. 0.41, r.i. 0.63). The taxon 

Charadriiformes was constructed from the character state of the hypothetical ancestor at node (a) in 

the previous analysis, see Fig. 33. 

(1) Monophyly of the Galliformes (within which the Megapodiidae form the sistergroup 

to the Cracidae and Phasianidae); 

(2) Sistergroup relationship of the Galliformes and the rest of the Neognathae (as 

represented in the analysis);

0.94 


0.70 

0.73 

0.88 

0.88 

0.93 

0.70 

0.99 

Rheidae 

Tinamidae 

Megapodiidae 

Cracidae 

Phasianidae 


Eurypygidae 

Rhynochetidae 


Cariamidae 


Psophiidae 

Rallidae 

Otididae 

Gruidae 

Aramidae 

Burhinidae 

Charadriiformes 


Anhimidae 

Anseranatidae 

Anatidae 


Ardeidae 

Scopidae 


Ciconiidae 


Figure 35. Parsimony Jackknifing analysis of the same 36 trees as those from which the strict consensus 

tree in Fig. 34 was calculated. Parsimony Jackknifing scores are given for all nodes that occur in more 

than 60% of the replications. 

(3) Sistergroup position of the Mesitornithidae in relation to all other non-galliform 

taxa, and 

(4) Monophyly of a clade consisting of the Phoenicopteridae, Anhimidae, Presbyornithidae, 

Anseranatidae and Anatidae.

466 


The result obviously does not corroborate the often suggested close affinity of 

anseriform and galliform birds (Seebohm, 1889; Garrod, 1873, 1874; Simonetta, 

1963; Dzerzhinsky, 1982, 1995; Cracraft, 1986, 1988; Cracraft & Mindell, 1989; 

Weber, 1993). Cracraft (1988) postulated 11 cranial synapomorphies for such a 

clade. An analysis of their homology, taxonomic distributions, and, in some cases, 

inter-dependence (Ericson, 1996), led to the retention of only two of Cracraft’s 

characters in this analysis. To evaluate the effect of the exclusion of the other nine 

characters on the phylogenetic reconstruction, a trial data set was constructed in 

which these were added to the original data matrix. Out of 38 most parsimonious 

trees obtained by Hennig86, the Galliformes and Anseriformes group together in only 

four trees. In the rest, the Anseriformes constitute the sister to the Phoenicopteridae. It 

can be concluded that the original data matrix contains an overwhelming amount 

of phylogenetic information against an anseriform galliform sistergroup relationship. 

Not even the inclusion of nine additional supposed synapomorphies for such a clade 

outweighs this information. 

Beyond doubt the family Presbyornithidae is a member of the order Anseriformes, 

and its relationships to other anseriforms are analysed in detail below. The outgroup 

of the Anseriformes is not unambiguously identified in the analysis. In the strict 

consensus tree, the Phoenicopteridae is the sister to the Anseriformes, but the 

confidence in this clade should not be too high, as evident from the Parsimony 

Jackknifing analysis (Fig. 35). Jackknifing of the data matrix collapses some of the 

branches present in the consensus tree, leaving us with a large group of ciconiiform 

and gruiform families that form an unresolved polytomy with the Anseriformes and 

Charadriiformes. The nodes of the two latter clades are strongly supported, however, 

scoring 0.90 and 0.99 respectively, in a Parsimony Jackknifing analysis. Although 

the monophyly of the Charadriiformes (including Pedionomidae) seldom is disputed, 

the taxonomic limits of the order have been more so. The arguments most often 

relate to the inclusion and/or exclusion of the families Jacanidae and Otididae 

(Lowe, 1925; Stresemann, 1934; von Boetticher, 1934). The present analysis keeps 

the Jacanidae well inside the Charadriiformes, while the Otididae are not recognized 

as a member of this taxon, or as its sistergroup. 

RELATIONSHIPS OF THE PRESBYORNITHIDAE WITHIN THE ANSERIFORMES 

After having established the general affinities of the Presbyornithidae with the 

Anseriformes, the focus shifts towards their precise position within this order. To 

this end, a phylogenetic analysis at the generic level with the Anseriformes and 

Presbyornithidae was conducted. Besides Presbyornis (family Presbyornithidae), eight 

anseriform genera were selected: Anhima and Chauna (Anhimidae), Anseranas (Anseranatidae), 

and Dendrocygna, Thalassornis, Stictonetta, Anser and Tadorna (Anatidae). 

The genera of Anatidae were chosen to represent major, early branches from the 

main anatid stem (Dendrocygna, Thalassornis, Stictonetta) recognized by Livezey (1986), 

as well as more derived anatid groups (Anser and Tadorna). Three genera serve as an 

outgroup belonging to the families Gruidae (Grus), Threskiornithidae (Threskiornis) 

and Phoenicopteridae (Phoenicopterus).


Character selection 

A set of 49 osteological characters (Table 2) was chosen partly from those 

characters that were variable at this phylogenetic level in the general analysis, and 

partly from characters used in previous studies of anseriform relationships. A majority 

of the latter characters were originally defined for a cladistic use by Livezey (1986), 

who in turn based his work partially on that of Woolfenden (1961). Some potentially 

useful characters of Livezey (1986) were not considered here because they either 

are ambiguously described or were found to have taxonomic distributions that differ 

from what was claimed (pers. obs.). The rejected characters are Livezey’s nos. 11, 

21, 23, 27, 32, 51, 62, 63, 79, 81, 99, 100, 101, 116 and 119 (1986:751ff.) All 

characters were treated as unordered. 

Character descriptions 

1. Cranium: fonticulus occipitalis present in adulthood (character no. 9 of Livezey, 1986) 


The loss of occipital fontanelles in adulthood is typical for the Anhimidae. 

2. Cranium: os frontale narrow and laterally rounded 

(0) no; (1) yes. 

In both Presbyornis and Tadorna, as well as Phoenicopterus, the frontals are rather narrow 

with the lateral margins smoothly rounded. 

3. Cranium: co-ossification of skull and lacrimals (character no. 10 of Livezey, 1986) 

(0) lacrimals unfused, or poorly fused, to skull with dorsal line of fusion clearly 

visible; (1) lacrimals well fused to skull. 

Livezey (1986:751) described the lacrimals in the Anhimidae as “fused to skull 

dorsally, small, nonpneumatic”, while those in Anseranas are regarded as unfused to 

skull. To me, the conditions in these taxa are very similar with the line of fusion 

clearly visible, both dorsally and ventrally. Although it can be suspected the lacrimals 

are truly fused in older individuals, it is hard to tell the fused condition from the 

unfused in most museum specimens that are inadequately cleaned. All Anatidae 

have the lacrimals fused to skull. In Presbyornis the lacrimals are unfused. 

4. Cranium: ventral surface of processus postorbitalis distinctly excavated 

(0) no; (1) yes. 

In all ingroup taxa, but not in the outgroup, the ventral surface of the processus 

postorbitalis is distinctly excavated. 

5. Cranium: basipterygoid processes 

(0) true, reptilian basipterygoid articulation; (1) absent; (2) rostropterygoid articulation. 

Basipterygoid processes are found in all ingroup taxa. Weber (1993) distinguishes 

between two kinds of basipterygian articulations: the true, reptilian and the rostropterygoid 

(see character no. 20 in first analysis). The Anhimidae are considered to 

conform to state 0 while all other ingroup taxa are assigned state 2. No outgroup 

taxon has functional basipterygoid processes, although the Phoenicopteridae may 

have rudimentary processes (Gadow, 1877:384; Seebohm, 1889:97).

468 

Table 2. Data matrix used in the second step of the analysis. 

Character no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 

Taxon 


Grus 1 0 0 0 1 0 0 0 0 0 1 0 0 ? 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 1 1 0 0 ? 0 0 1 0 1 0 0 0 0 0 1 1 0 0 

Threskiornis 1 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 1 1 1 0 1 0 0 0 0 0 

Phoenicopterus 1 1 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 1 0 0 0 1 0 1 1 0 1 

Anhima 0 0 0 1 0 0 0 1 0 0 1 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1 0 1 0 0 1 0 1 0 1 0 0 1 1 0 1 0 0 1 1 0 0 0 0 0 0 

Chauna 0 0 0 1 0 0 0 1 0 0 1 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1 0 1 0 1 1 0 1 0 1 0 0 1 1 0 1 0 0 1 1 0 0 0 0 0 0 

Anseranas 1 0 0 1 2 0 1 1 1 1 1 1 1 1 0 1 1 1 0 0 1 0 1 0 0 1 1 1 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 1 0 0 0 0 0 0 

Dendrocygna 1 0 1 1 2 1 1 1 1 1 1 1 1 2 1 1 1 0 0 0 1 0 1 1 1 1 1 0 1 1 0 1 0 0 0 1 0 0 0 0 0 1 2 0 1 1 1 1 1 0 0 

Thalassornis 1 0 1 1 2 1 1 1 1 1 1 1 1 2 1 1 1 0 0 0 1 1 1 1 1 1 1 0 1 1 0 1 2 1 0 1 0 0 0 0 0 1 2 0 1 1 1 1 1 1 0 

Anser 1 0 1 1 2 1 1 1 1 1 0 1 1 2 1 1 1 0 0 0 1 1 1 1 1 1 1 0 0 1 0 1 0 0 0 1 0 0 0 1 0 1 2 0 1 1 1 1 1 1 0 

Stictonetta 1 0 1 1 2 1 1 1 1 1 1 1 1 2 1 1 1 0 0 0 1 1 1 1 1 1 1 0 1 1 0 1 0 1 0 1 1 0 0 1 0 1 2 0 1 1 1 1 1 1 0 

Tadorna 1 1 1 1 2 1 1 1 1 1 0 1 1 2 1 1 1 1 0 0 1 1 1 1 1 1 1 0 0 1 0 1 0 1 0 1 1 0 0 1 0 1 2 0 1 1 1 1 1 1 0 

Presbyornis 1 1 0 1 2 0 ? 1 1 1 1 0 1 1 ? 1 1 0 1 ? 1 0 0 0 0 0 ? 0 0 0 0 1 0 0 0 0 0 0 0 1 0 1 1 0 1 0 0 0 1 0 1


6. Cranium: ventral margin of rostrum parasphenoidale 

(0) clearly angled; (1) gradually sloping toward the nasal-frontal hinge. 

The ventral margin of rostrum parasphenoidale slopes gradually toward the nasalfrontal 

hinge in Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna. In the other 

taxa studied the rostrum is clearly angled. 

7. Facies: pterygoid-palatine articulation a ball-and-socket arrangement involving two extensions 

of the pterygoid (character no. 18 of Livezey, 1986) 

(0) no; (1) yes. 

A ball-and-socket arrangement, involving two extensions of the pterygoid, occur in 

Anseranas and Anatidae. This morphology is unknown in Presbyornis due to lack of 

adequate specimens. 

8. Facies: internal laminae of palatines obsolete 

(0) no; (1) yes. 

In all ingroup taxa, but not in the outgroup, the internal laminae of the palatines 

are obsolete. 

9. Facies: position of processus jugale of os maxillare relative to maxillopalatinum 

(0) no; (1) yes. 

In all taxa, except the Anhimidae and the outgroup, the processus jugale of maxillare 

lays ventral of maxillopalatinum (Shufeldt, 1901:300). 

10. Facies: bill broad and spatulate 

(0) no; (1) yes. 

A broad, spatulate (duck-like) bill is typical of all ingroup taxa, except the Anhimidae. 

11. Quadratum: lateral view (character no. 15 of Livezey, 1986) 

(0) not squarish, with variably deeply curved dorsal margin between orbital and otic 

processes; (1) squarish, with dorsal margin straight. 

The quadrate is squarish with a straight dorsal margin between the orbital and otic 

processes in most Anseriformes and Presbyornis. This morphology does not occur in 

Anser or Tadorna. Of the outgroup taxa, the quadrate is squarish only in Grus. 

12. Quadratum: processus mandibularis inflated posterior to the quadratojugal articulation 

(0) no; (1) yes. 

An inflated processus mandibularis of the quadrate occurs in Anhima, Chauna, 

Anseranas, Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna, but not in Presbyornis 

(Olson & Feduccia, 1980b:15) nor in the outgroup. 

13. Mandibula: quadratal articulation 

(0) basically a three-condyle articulation, with cotyla medialis and cotyla lateralis 

separated by a shallow groove (a distinct posterior cotyla may or may not be present); 

(1) two-condyle articulation, with cotylae medialis and lateralis large and separated 

by an antero-posteriorly oriented crista intercotylaris. 

A two-condyle quadratal articulation is present in all ingroup taxa, but not in the 

outgroup. 

14. Mandibula: recessus conicalis 

(0) absent; (1) present, shallow; (2) present, extremely deep. 

A deep recessus conicalis is present in Dendrocygna, Thalassornis, Anser, Stictonetta and 

Tadorna. The recessus is shallow in Presbyornis and Anseranas, and is lacking entirely 

in the Anhimidae. Lebedinsky (1920:100) claims that all anseriforms possess the

470 


deep recessus conicalis, but it should be borne in mind that the Anhimidae and 

Anseranas were not included in his study. 

15. Mandibula: foramen pneumaticum of processus mandibulae medialis 

(0) present, often close to the medial tip; (1) absent. 

The processus mandibulae medialis is pneumatized in the outgroup taxa and in 

Anseranas, Anhima and Chauna (lacking in some individuals of the latter two genera, 

but both assigned state 0), but not in the other taxa. This morphology is unknown 

in Presbyornis due to lack of adequate specimens. 

16. Mandibula: processus lateralis 


A processus lateralis of the mandible occurs in all ingroup taxa, except the Anhimidae. 

It is lacking in Grus, Threskiornis and Phoenicopterus. 

17. Mandibula: deep groove in the ventral surface of the anterior portion of the mandibular rami 


In all ingroup taxa except the Anhimidae, the mandible has the ventral surface of 

the anterior portion of the rami deeply grooved (Olson & Feduccia, 1980b:15). This 

condition is not found in Grus, Threskiornis or Phoenicopterus. 

18. Vertebrae thoracicae: notarium present 

(0) yes; (1) no. 

A notarium is present in Anhima, Chauna, Anseranas, Tadorna and Anser (lacking in 

some individuals, but the taxon assigned state 0), as well as in the outgroup. A 

notarium is lacking in Dendrocygna, Thalassornis and Stictonetta, and, most likely, 

Presbyornis. 

19. Vertebrae thoracicae: the caudalmost thoracic vertebrae are pleurocoelous, sometimes with 

pneumatization 

(0) no; (1) yes. 

Only the Anhimidae and Presbyornis possess pleurocoelous thoracic vertebrae. 

20. Costae: processus uncinatus (character no. 91 of Livezey, 1986) 


Uncinate processes of the costae are present in all ingroup and outgroup taxa, as 

well as in almost all birds, except the Anhimidae. 

21. Pelvis: mediolateral compression of the corpus of the synsacro-thoracic and synsacro-lumbar 

vertebrae 

(0) corpi of the first few synsacral vertebrae with about equal mediolateral compression; 

(1) corpus of the first synsacro-thoracic vertebra considerably more mediolaterally 

compressed than the following vertebrae. 

Mediolaterally compressed vertebral corpi are found in both outgroup and ingroup 

taxa. In the former and the Anhimidae, all the first few synsacral vertebrae are 

equally compressed. In the remaining taxa, however, the first synsacro-thoracal 

vertebra is considerably more compressed than are the rest. 

22. Pelvis: caudal margin (character no. 114 of Livezey, 1986) 

(0) ischium extending well caudal to ilium; (1) variable, but ischium and ilium 

roughly equal in caudal extent, forming an oblique sloping margin, with elements 

typically separated posteriorly by a distinct notch.


The ischium and ilium extend roughly equally far distad in Thalassornis, Anser, 

Stictonetta and Tadorna, as well as in Grus and Threskiornis. 

23. Pelvis: dorsolateral crests (character no. 118 of Livezey, 1986) 

(0) distinct to caudal margin of pelvis; (1) becomes obsolete cranial to caudal margin. 

The dorsolateral crests of pelvis becomes obsolete cranial to the caudal margin in 

Anseranas, Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna. 

24. Pelvis: recessus iliacus (character no. 120 of Livezey, 1986) 


A recessus iliacus is commonly found in the Class Aves, although it is absent in 

many anseriforms. Among the ingroup taxa, it is absent in Dendrocygna, Thalassornis, 

Anser, Stictonetta and Tadorna. It is also lacking in Phoenicopterus. 

25. Pelvis: ventral margin of ischium with a cranially projected hook close to processus terminalis 

(0) no; (1) yes. 

In Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna the ventral margin of the 

ischium is cranially hooked close to the processus terminalis. In the other taxa the 

ventral margin is straight. 

26. Sternum: left sulcus articularis coracoideus overlaps the right sulcus 

(0) yes; (1) no. 

Sulci articularis coracoideus that overlap medially occur in Phoenicopterus, Threskiornis 

and Presbyornis, but are absent in other taxa. 

27. Sternum: intermuscular line (character no. 88 of Livezey, 1986) 

(0) angles medially to carinal base well anterior to posterior edge of plate; (1) extends 

posteriorly to posterior margin of plate. 

The intermuscular lines of the sternum extend posteriorly to the posterior margin 

of the plate in Anseranas, Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna. This 

morphology is unknown in Presbyornis due to lack of adequate specimens. 

28. Sternum: pars cardiaca largely covered by numerous small foramina and bony striations 

(0) no; (1) yes. 

The possession of a pars cardiaca of the sternum covered by numerous small 

foramina and bony striations is typical of the Anhimidae and Anseranas (Woolfenden, 

1961:36; Livezey, 1986:752). 

29. Coracoid: depression on ventral surface anterior to sternal facet (character no. 96 of Livezey, 

1986) 

(0) absent; (1) present, typically deep. 

A deep depression on the ventral surface of the coracoid, anterior to the sternal 

facet, is present in Dendrocygna, Thalassornis and Stictonetta. 

30. Coracoid: procoracoid foramen (character no. 92 of Livezey, 1986) 


The absence of a procoracoid foramen is a morphology shared by Dendrocygna, 

Thalassornis, Anser, Stictonetta and Tadorna. In most individuals of Chauna this foramen 

is also lacking (it was found in only one out of 14 individuals examined) and, 

following the majority, this genus is here assigned state 1. 

31. Furcula: clavicles very flattened antero-posteriorly (character no. 104 of Livezey, 1986) 

(0) no; (1) yes. 

Antero-posteriorly very flattened clavicles occur in the Anhimidae.

472 


32. Scapula: coracoidal articulation (character no. 109 of Livezey, 1986) 

(0) equal to acromion in proximal extent; (1) distinctly distal to acromion. 

The coracoidal articulation of the scapula is situated distinctly distal to the acromion 

in Presbyornis, Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna. This is also the 

case in Phoenicopterus. 

33. Humerus: capital shaft ridge (character no. 22 of Livezey, 1986) 

(0) directed toward head; (1) directed toward external tuberosity. 

The ridge on the capital shaft is directed toward the external tuberosity only in 

Thalassornis, Stictonetta and Tadorna (an examination of two specimens of Thalassornis 

supports Livezey’s [1986:751, Supplement] tentative assignment of this genus to 

state 1). This condition is also found in Grus. 

34. Humerus: prominent tubercle near the distal end of the deltoid crest (character no. 31 of 

Livezey, 1986) 


The presence of a tubercle is an autapomorphy of the Anhimidae. 

35. Carpometacarpus: prominent notch distally on the external rim of carpal trochlea (character 

no. 38 of Livezey, 1986) 

(0) no; (1) yes. 

In most anseriform genera, this is a fairly clear-cut character which either have the 

external rim of the carpal trochlea essentially continuous, or with a prominent notch 

distally. Two taxa, Dendrocygna and Thalassornis, were incorrectly assigned to state 0 

by Livezey (1986:Supplement), however. Actually, the condition in Dendrocygna was 

described by Woolfenden (1961:23) as being slightly notched (no specimen of 

Thalassornis was available to him). Consequently, Dendrocygna and Thalassornis are 

here assigned the derived state along with Anser, Stictonetta and Tadorna. Presbyornis 

lacks a prominent notch. 

36. Carpometacarpus: dorsal surface of metacarpal II rounded proximally (character no. 39 of 


(0) no; (1) yes. 

The dorsal surface of metacarpal II is proximally rounded only in Stictonetta and 

Tadorna. 

37. Carpometacarpus: processus extensorius with a long, bony spur (character no. 42 of Livezey, 

1986) 

(0) no; (1) yes. 

To have the metacarpal I process extremely long and spurred is an autapomorphy 

of the Anhimidae. 

38. Carpometacarpus: distal extension of trochlea dorsalis 

(0) falling short of trochlea ventralis; (1) equals or exceeds the distal extension of 

trochlea ventralis. 

Only in the Anhimidae does the dorsalis extend equally far distally, or farther distad 

of trochlea ventralis. 

39. Carpometacarpus: attachment site of M. extensor carpi ulnaris (character no. 43 of Livezey, 

1986) 

(0) attachment of M. extensor carpi ulnaris positioned completely proximal of the


proximal point of fusion between metacarpals II and III; (1) attachment approximately 

at level with the point of fusion. 

The M. extensor carpi ulnaris attaches at level with the proximal point of fusion 

between metacarpals II and III in Presbyornis, Anser, Stictonetta and Tadorna. In all but 

one (USNM 347638) Anseranas specimens, the attachment is positioned proximal to 

the point of fusion, and this genus is here assigned state 0. It is positioned 

approximately level with the point of fusion in Grus and Threskiornis. 

40. Carpometacarpus: prominent spur on tuberosity of metacarpal II (character no. 40 of Livezey, 

1986) 


This is an autapomorphy for the Anhimidae. 

41. Carpometacarpus: distal extension of facets for digits II and III (character no. 45 of Livezey, 

1986) 

(0) facets essentially equal in distal extension; (1) facet for digit III extending farther 

distally than facet for digit II. 

To have the facet for digit III extending farther distally than the facet for digit II 

is an autapomorphic condition for the Anhimidae. 

42. Femur: posterior intermuscular lines (character no. 58 of Livezey, 1986) 

(0) lines not fused proximally; (1) lines fused proximally, swinging toward trochanter; 

(2) lines fused proximally, following internal edge of shaft. 

In all non-anhimid anseriforms (besides Biziura in which the diving specializations 

of the leg makes osteological comparisons difficult) and Presbyornis, the ‘posterior 

intermuscular line’ is in fact two intermuscular lines (often visible in the distal part 

of the shaft) that are fused proximally. The Anhimidae have the two lines unfused, 

while the intermuscular line swings laterally toward the trochanter in Anseranas and 

Presbyornis. Grus and Phoenicopterus have state 0 and Threskiornis state 1. Note that the 

definition of this character is slightly altered from that given by Livezey (1986:752). 

43. Tibiotarsus: shape of crista cnemialis cranialis 

(0) cranioproximally well developed; (1) truncated cranially and extending about 

equally far proximal as crista patellaris. 

A cranioproximally well developed crista cnemialis cranialis is present in Anseranas, 

Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna, as well as in Presbyornis. Phoenicopterus 

has the crest well developed, whereas it is truncated in Grus and Threskiornis. 

44. Tibiotarsus: position of the distal opening of canalis extensorius relative to the medial and 

lateral condyles 

(0) closer to the medial condyle than to the lateral; (1) equally far from either 

condyle, or closer to the lateral. 

To have the distal opening of canalis extensorius positioned equally far from either 

of the condyles is found in all ingroup taxa, but not in the outgroup. 

45. Tarsometatarsus: position of calcaneal ridges of hypotarsus relative to midline of shaft (character 

no. 72 of Livezey, 1986) 

(0) on midline, without depression on internal margin; (1) lateral to midline, bordered 

medially by depression. 

The calcaneal ridges of the hypotarsus are positioned lateral to the midline of the 

shaft in Presbyornis, Anhima, Chauna and Anseranas. Due to ambiguities in counting of 

number of ridges, the definition of this character has been altered from that given 

by Livezey (1986:752). Character state 1 is also found in Threskiornis and Phoenicopterus.

474 


46. Tarsometartasus: posterior opening of distal foramen (character no. 77 of Livezey, 1986) 

(0) directed posteriorly, flush with surface of shaft; (1) directed disto-posteriorly, 

recessed in depression immediately proximal to symphysis of trochleae for digits III 

and IV. 

Having the posterior opening of the distal foramen directed disto-posteriorly, flush 

with surface of shaft, is typical of Dendrocygna, Thalassornis, Anser, Stictonetta and Tadorna. 

47. Tarsometatarsus: facet for metatarsal I (character no. 71 of Livezey, 1986) 

(0) deep; (1) obsolete. 

The facet for metatarsal I (hallux) is obselete in Grus, Phoenicopterus, Dendrocygna, 

Thalassornis, Anser, Stictonetta and Tadorna. 

48. Tarsometatarsus: trochlea for digit II proximal to trochlea for digit IV (character no. 68 of 


(0) no; (1) yes. 

Having the trochlea for digit II extending less far distally than the trochlea for digit 

IV is a morphology shared by Presbyornis, Dendrocygna, Thalassornis, Anser, Stictonetta 

and Tadorna. This is also true in Grus and Phoenicopterus, but not in Threskiornis. 

49. Tarsometatarsus: groove in trochlea for digit II (character no. 74 of Livezey, 1986) 

(0) absent; (1) present, but posterior terminus of groove variable in extent. 

A groove in trochlea for digit II is a shared morphology in Thalassornis, Anser, 

Stictonetta and Tadorna. 

50. Phalanges pedis: third phalanx of digit IV distinctly longer than the fourth phalanx 

(0) no; (1) yes. 

A distinctly longer third than fourth phalanx of digit IV is found only in Presbyornis 

of the ingroup taxa, as well as in Phoenicopterus (Kessler, 1841). 

Results 

The phylogenetic analysis generated a single most parsimonious tree (82 steps, 

c.i. 0.65, r.i. 0.81). As evident in Figure 36, Presbyornis is maintained well inside the 

anseriform clade as suggested by the result of the general analysis. The unambiguous 

synapomorphies for the Anseriformes (including the Presbyornithidae) are the 

distinctly, ventrally excavated processus postorbitalis (character no. 4), palatine with 

the internal laminae obsolete (no. 8), processus mandibularis of the quadrate inflated 

posterior to the quadratojugal articulation (no. 12), two-condyle articulation between 

the quadrate and mandibula (no. 13), and a tibiotarsus with the distal opening of 

canalis extensorius equally far from either condyle (no. 44). 

Two types of basipterygoid articulations are possessed by the Anseriformes. The 

true reptilian type (character no. 5, state 0) occurs in the Anhimidae, parallelling 

the condition of many charadriiform birds. All other extant anseriforms and Presbyornis 

have a so-called rostropterygoid articulation (following Weber, 1993). 

In accordance with the traditional view (Livezey, 1986), the Anhimidae are the 

first to branch off from the main anseriform stem. The Anhimidae share a number 

of synapomorphies that sets them apart from other anseriforms (Fig. 36). 

The singularity of the endemic, monotypic Australian Anseranas, is evident from 

morphological, parasitological and biochemical studies (von Boetticher & Eichler, 

1951; Delacour, 1954; Woolfenden, 1961; Bottjer, 1983; Livezey, 1986), and its

22 

34 

40 

48 

49 

Grus 

22 

40 

43 

44 

Threskiornis 

11 

26 

46 

2 

24 

(1) 32 

48 

49 

51 


Phoenicopterus 

Anhima 

1 

5 

14 

20 

31 

35 

38 

39 

41 

42 

19 

44 

30 

(0) 

(0) 

Chauna 

4 

8 

13 

45 

12 

28 

Anseranas 

2 

19 

26 

40 

51 

12 

23 

5 

7 

9 

10 

16 

17 

21 

33 

27 

23 

43 

Presbyornis 

(2) 

(1) 

(1) 

15 

18 

32 

49 

28 

Dendrocygna 

33 

3 

6 

14 

25 

36 

43 

47 

29 

24 

30 

46 

48 

Thalassornis 

(2) 

(2) 

(2) 

50 

22 

34 

Stictonetta 

37 

40 

34 

37 

synapomorphy 

Anser 

11 

29 

2 

18 

character transformation 

with reversal further up 

convergent character 

transformation 

reversal 

Tadorna 

Figure 36. The single most parsimonious tree (82 steps, c.i. 0.65, r.i. 0.81) in the analysis of the main 

groups of the Anseriformes. The character transformations are traced in the tree under the assumption 

that reversals have been more common than parallelisms. 

placement in its own family, Anseranatidae, is doubtless justified. In this analysis, 

Anseranas is the sister to a clade consisting of the Anatidae and Presbyornis. The latter 

are separated from the Anhimidae and Anseranatidae by the loss of a pneumatization

476 


of the processus mandibulae medialis (no. 15), loss of a notarium (character no. 18, 

reversed in Tadorna), a sternum that lacks foramina and bony striations in the pars 

cardiaca (no. 28), a scapula with a long and pointed acromion (no. 32), and a 

tarsometatarsus that has the medial trochlea located in a more proximal and elevated 

position (no. 48). The phylogenetic analysis also reveals many autapomorphies of 

Presbyornis, but, generally speaking, most of these are likely to be plesiomorphic 

within the order (see Discussion). 

Among the anatid genera, Dendrocygna is the sister to the rest. A proximity to 

Dendrocygna has been suggested for Stictonetta by Woolfenden (1961) and for Thalassornis 

by Johnsgard (1967), Raikow (1971), among others. 

DISCUSSION 

It is evident that the Presbyornithidae are truly anseriform birds. They are even 

the sister of the Anatidae, whereas the Anhimidae and Anseranatidae fall outside 

this clade. The earliest Presbyornithidae date to the Late Paleocene [given the many 

similarities of the Presbyornithidae with members of the early Paleogene ‘formfamily’ 

Graculavidae (sensu Olson & Parris, 1987), the claimed presbyornithid 

affinities of Late Cretaceous fossils collected in Antarctica (Noriega & Tambussi, 

1995) need verification] indicating that the split between them and the Anseranatidae 

occurred at least 60 Mya (million year ago). Until recently, the earliest fossils of the 

Anseriformes (i.e. of the Anatidae given that no anhimid or anseranatid palaeospecies 

has been described) are from the Early Oligocene (c. 35 Mya) of Europe (Olson, 

1985). The Anatidae do not, however, become common in the fossil bird faunas 

until the Neogene (op. cit.). If the fossil record is reliable in this respect, and given 

the fact that postcranial elements dominate, this could mean that the typical anatid 

postcranial anatomy had not evolved until then. 

Although the Presbyornithidae are similar to the Anseranatidae and Anatidae in 

many respects, their morphology also indicates specialization. Perhaps the most 

striking characteristic of the Presbyornithidae is the long, slender legs, which contrast 

with the members of the closely related family Anatidae that typically have rather 

short, stubby legs (an obvious adaptation to aquatic life). What then, is the plesiomorphic 

condition of the Presbyornithidae–Anatidae clade, long legs or short legs? 

Considering the result in the general analysis, it seems possible to argue that longleggedness 

is the plesiomorphic condition in the group of birds with which the 

Anseriformes are most closely affiliated, i.e. the families traditionally placed in the 

orders Ciconiiformes and Charadriiformes. Among these taxa, the Anseriformes is 

the only large group of birds with consistently short legs. However, as is evident 

from Figure 37 in which some anseriform genera are lined up in the branchingsequence 

order postulated by Livezey (1986), the most long-legged members of the 

order prove to be those that branched off earliest from the main anseriform stem. 

The shortest legs are found in members of the most recent branches, suggesting 

that long-leggedness is primitive in the Anseriformes. Hence, the long legs in the 

Presbyornithidae conceivably reflect the primitive condition in the order. It seems 

probable, however, that the Presbyornithidae had even longer legs than would be 

expected for an early anseriform bird (Fig. 37). 

Other autapomorphic features of the Presbyornithidae relative to other Anseriformes 

are: (i) a sternum with the two sulci overlapping medially (certainly a


0 

1.0 2.0 3.0 

Anhimidae 

Anseranas 

Presbyornis 

Dendrocygna 

Geese, swans 

Stictonetta 

Plectropterus 

"Shelducks" 

Aix, Cairina 

Nettapus 

"Higher" dabblers 

and divers 

Figure 37. Selected anseriform genera ordered according to their branching-sequence (following 

Livezey 1986), with Presbyornis positioned after Anseranas but before the Anatidae, as evident from the 

present analysis. The scale indicates the relative leg length, calculated as the sum of the lengths of the 

tibiotarsus and tarsometatarsus divided by the pelvis length (metrical data from Verheyen, 1953). 

plesiomorphic condition present in flamingos, ibises and many other ciconiiform 

and charadriiform families); (ii) a sternum with a four-notched posterior margin 

(also a plesiomorphic condition within the neognaths, found in several fossils clearly 

referable to modern taxa in which it has been lost); (iii) a humerus with a wide and 

non-pneumatic fossa (possibly another plesiomorphy since a humerus with a wide, 

non-pneumatic fossa occurs in most charadriiforms), and (iv) innominate bones 

unfused to the saccrum (a plesiomorphic condition occurring in charadriiforms, but 

not in ciconiiform or gruiform birds). 

The Presbyornithidae share the pleurocoelous thoracic vertebrae with the Anhimidae. 

Also, this morphology is most likely primitive in birds, and may be found in 

many Eocene birds. It is likely that the pleurocoely, as well as most other plesiomorphic 

morphologies in birds listed above, have been lost independently in many lineages. 

It was stated above that no fossil Anhimidae have been described, but a still 

unpublished find of an anhimid is known from the Eocene of Wyoming (Peter 

Houde, pers. comm.). This specimen consists of an almost complete articulated 

skeleton including the skull of a single individual. Courtesy of Peter Houde and 

Storrs L. Olson, I have had the opportunity to study this specimen briefly, and 

there is no doubt it should be referred to the Anhimidae. The braincase is very 

similar to that of extant anhimids, as is the narrow, slightly recurved bill with very 

large nasal septum. It agrees with the Anhimidae, and differs from the Anseranatidae 

and Anatidae, in lacking the groove in the mandibular ramus. In contrast to living 

anhimids, however, the mandible possesses the prominent, laterally located coronoid 

process diagnostic of the Anseranatidae and Anatidae. The size and shape of this 

process in the Eocene bird, suggests that the anhimid skull, in which the bill 

resembles that of a galliform bird, evolved from an anatid design. This supports the 

theory that the Anhimidae have a filter-feeding ancestor, as is also indicated by the 

presence of vestigal lamellae in the rhamphotheca (Olson & Feduccia, 1980b).

478 


In contrast to the anhimid-like skull, the postcranial skeleton of this Eocene bird 

is only remotely reminiscent of the Anhimidae. In part this could be the result of 

the extreme pneumatic and inflated condition to be found in the skeleton of living 

anhimids (DeMay, 1940), which has distorted the morphology almost beyond 

recognition. The Wyoming bird is not at all pneumatic or inflated. The postcranial 

skeleton thus approaches what I suspect to be the plesiomorphic morphology of the 

order Anseriformes, and, not surprisingly, several elements are almost identical to 

those in the Presbyornithidae, e.g. the carpometacarpus, coracoid, furcula and 

tibiotarsus. Furthermore, the elements that differ the most from the Presbyornithidae, 

(e.g. the cranium, femur, humerus and scapula), are those that most closely match 

the Anhimidae. 

It has been suggested that the Anseriformes are most closely related to the 

Charadriiformes (Olson & Feduccia, 1980b). The present results contradict this 

hypothesis. On the other hand, the Charadriiformes, with the Burhinidae as their 

most basal member, is a part of the same unresolved clade as are the Anseriformes 

(including the Presbyornithidae). In many respects, the postcranial anatomy of the 

Burhinidae and Presbyornithidae are strikingly similar and a very similar morphology 

also occurs in certain Late Cretaceous and Paleogene birds (i.e. the ‘form-family’ 

Graculavidae, Olson & Parris, 1987). It seems likely this anatomy is plesiomorphic 

within the group of birds from which the Anseriformes, Charadriiformes and 

Ciconiiformes (sensu Wetmore, 1960) stem. The skeletal resemblence between the 

Presbyornithidae and some charadriiform birds may thus be due to the retention 

of primitive characters in both lineages. 

Obviously, the most important contribution of the Presbyornithidae to avian 

systematics may not lie in the reconstruction of the relationships of nonpasseriform 

families per se. The exclusion of the Presbyornithidae from the data matrix has no 

effect on the phylogenetic reconstruction in terms of the number of most parsimonious 

trees found, or their topologies. However, the retention of many obviously plesiomorphic 

morphologies in the presbyornithid skeleton provides information on 

character evolution in nonpasseriform birds. Furthermore, by the allocation of the 

Presbyornithidae to the Anseriformes, it is suggested that their filter-feeding adaptations 

evolved well before the aquatic adaptations typical of many modern 

anseriforms. 

Two major different filter-feeding adaptations occur in the Class Aves (in Phoenicopteridae 

and Anseriformes, respectively). As we have seen, the oldest anseriform 

discovered to date is Presbyornis of the early Paleogene. The oldest phoenicopterid 

described is the contemporary Juncitarsus of North America and Europe (Olson & 

Feduccia, 1980a; Peters, 1987). Based on the fossil evidence it can thus be hypothesized 

that the two filter-feeding adaptations represented by the anseriforms 

and pheonicopterids evolved more or less simultaneously in the Late Cretaceous 

or Early Tertiary. The many postcranial similarities of Presbyornis and Juncitarsus 

furthermore suggest that these two phyletic lineages derive from the same group of 

closely related wading birds that gave rise to the modern Anseriformes and Ciconiiformes 

(Ericson, in press). The impetus for this parallel evolution of filterfeeders 

might very well have been the same, i.e. the opportunity to feed on planktonic 

invertebrates and algae (Feduccia, 1977, 1978), a food resource that may not have 

been exploited by birds earlier.


ACKNOWLEDGEMENTS 

This study was initiated during a stay as a postdoctoral fellow at the Department 

of Vertebrate Zoology, National Museum of Natural History, Washington, D.C., 

in 1989–90. The postdoctoral grant was financed by the Swedish Natural Science 

Research Council. My deepest gratitude is directed towards my advisor Dr Storrs 

L. Olson for inviting me to study Presbyornis, and for his constant support of the 

work. I also want to thank the other staff members of the Division of Birds for 

making my stay very rewarding and for facilitating the use of the excellent collections 

in their care. Access to the collections at the American Museum of Natural History 

was kindly granted by Dr François Vuilleumier and Dr Allison Andors. The 

manuscript has benefited greatly from the comments by Dr Alan Feduccia, Dr Cyril 

Walker and two anonymous reviewers. Many thanks also to Björn Lindsten who 

drew Figures 5, 7–9, 11, 15, 21, 23, 24, 27, 29, 31 and 32. 

REFERENCES 

Andors A. 1988. Giant groundbirds of North America (Aves, Diatrymidae). Unpublished Ph.D. 

Dissertation, Columbia University, New York. 

Ballmann P. 1979. Fossile Glareolidae aus dem Miozän des Nördlinger Ries. Bonner Zoologische Beiträge 

30: 52–101. 

Ballmann P, Adrover R. 1970. Yacimiento paleontológico de la cueva de Son Bauzà (Mallorca). 

Acta Geológica Hispánica 5: 58–62. 

Baumel JJ, King AS, Lucas AM, Breazile JE, Evans HE, eds. 1979. Nomina Anatomica Avium. 

New York: Academic Press, 637 pp. 

Baumel JJ, King AS, Breazile JE, Evans HE, Vanden Berge JC, eds. 1993. Handbook of Avian 

Anatomy: Nomina Anatomica Avium. 2nd edition. Cambridge, Mass.: Nuttall Ornithological Club, 779 

pp. 

Beddard FE. 1890. On the anatomy of Podica senegalensis. Proceedings of the Zoological Society of London 

1890: 425–443. 

Bledsoe AH. 1988. A phylogenetic analysis of postcranial skeletal characters of the ratite birds. Annals 

of Carnegie Museum 57: 73–90. 

Bock WJ. 1963. The cranial evidence for ratite affinities. Proceedings of the XIII International Ornithological 

Congress. American Ornothologists’ Union, 39–54. 

Bock WJ, McEvey A. 1969. Osteology of Pedionomus torquatus (Aves: Pedionomidae) and its allies. 

Proceedings of the Royal Society of Victoria 82: 187–232. 

Boetticher H von. 1934. Kurze phylogenetisch-systematische Uebersicht der regenpfeierartigen 

Vögel (Charadriiformes) und ihrer nächsten naturlichen Verwandten nach dem heutigen Stand 

unter Kenntnisse. Kocsag (Budapest) 7: 1–25. 

Boetticher H von, Eichler W. 1951. Parasitophyletische Studien zur Ornithosystematik. I. Die 

Acidoproctidae der Anseres. Zoologische Garten 19: 121–126. 

Bottjer PD. 1983. Systematic relationships among the Anatidae: an immunological study with a 

history of anatid classification and system of classification. Unpublished Ph.D. thesis, Yale University, 

New Haven, Connecticut, 

Chiappe LM, Calvo JO. 1994. Neuquenornis volans, a new Late Cretaceous bird (Enantiornithes: 

Avisauridae) from Patagonia, Argentina. Journal of Vertebrate Paleontology 14: 230–246. 

Cottam PA. 1957. The pelecaniform characters of the skeleton of the shoe-bill stork, Balaeniceps rex. 

Bulletin of the British Museum (Natural History) Zoology 5: 49–72. 

Cracraft J. 1968. The lacrimal-ectethmoid bone complex in birds: a single character analysis. 

Proceedings of the Zoological Society of London 80: 316–359. 

Cracraft J. 1970. A new species of Telmabates (Phoenicopteriformes) from the Lower Eocene of 

Patagonia. Condor 72: 479–480. 

Cracraft J. 1974. Phylogeny and evolution of the ratite birds. Ibis 116: 494–521.

480 


Cracraft J. 1980. Phylogenetic theory and methodology in avian paleontology: a critical appraisal. 

Natural History Museum, Los Angeles County, Contributions to Sciences 330: 9–16. 

Cracraft J. 1981. Toward a phylogenetic classification of the recent birds of the world (Class Aves). 

Auk 98: 681–714. 

Cracraft J. 1985. Monophyly and phylogenetic relationships of the Pelecaniformes: a numerical 

cladistic analysis. Auk 102: 834–853. 

Cracraft J. 1986. The origin and early diversification of birds. Paleobiology 12: 383–399. 

Cracraft J. 1988. The major clades of birds. In: Benton MJ, ed. The Phylogeny and Classification of the 

Tetrapods. Vol. I. Oxford: Clarendon Press, 333–355. 

Cracraft J, Mindell DP. 1989. The early history of modern birds: a comparison of molecular and 

morphological evidence. In: Fernholm B, Bremer K, Jörnvall H, eds. The Hierarchy of Life. Amsterdam: 

Elsevier Science Publishers B.V. (Biomedical Division), 389–403. 

de Beer GR. 1956. The evolution of ratites. Bulletin of the British Museum (Natural History) Zoology 4: 

57–76. 

Delacour J. 1954. Waterfowl of the world, vol. 1. London: Country Life Ltd, 284 pp. 

DeMay IS. 1940. A study of the pterylosis and pneumaticity of the screamer. Condor 42: 112–118. 

Dzerzhinsky FYa. 1982. [Adaptive features in the structure of maxillary system in some Anseriformes 

and probable ways of evolution of the order]. Zoologicheskij Zhurnal 61: 1031–1041. (In Russian with 

English summary). 

Dzerzhinsky FYa. 1995. Evidence for a common ancestry of the Galliformes and Anseriformes. 

Courier Forschungsinstitut Senckenberg 181: 325–336. 

Elzanowski A. 1977. On the role of basipterygoid processes in some birds. Verhandlungen der Anatomischen 

Gesellschaft 71: 1303–1307. 

Ericson PGP. 1996. The skeletal evidence for a sister-group relationship of anseriform and galliform 

birds—a critical evaluation. Journal of Avian Biology 27: 195–202. 

Ericson PGP. (in press). New material of Juncitarsus (Phoenicopteriformes) with a guide for 

differentiating that genus from the Presbyornithidae (Anseriformes). In: Olson, SL, ed. Avian 

Paleontology at the Close of the 20th Century. Proceedings of the 4th International Meeting of the Society 

of Avian Paleontology and Evolution. Washington, D.C., 4–7 June 1996. Smithsonian Contributions to 

Paleobiology.. 

Farris JS. 1995. Guide to the Parsimony Jackknifer. Swedish Museum of Natural History. 

Farris JS, Albert WA, Källersjö M, Lipscomb D, Kluge AG. 1996. Parsimony jackknifing 

outperforms neighbor-joining. Cladistics 12: 99–124. 

Feduccia A. 1976. Osteological evidence for the shorebird affinities of the flamingos. Auk 93: 587–601. 

Feduccia A. 1977. Hypothetical stages in the evolution of ducks and flamingos. Journal of Theoretical 

Biology 67: 715–721. 

Feduccia A. 1978. Presbyornis and the evolution of ducks and flamingos. American Scientist 66: 298–304. 

Feduccia A, McGrew PO. 1974. A flamingolike wader from the Eocene of Wyoming. Contributions 

to Geology 13: 49–61. 

Fürbringer M. 1888. Untersuchungen zur Morphologie und Systematik der Vögel. Vols. 1–2. Amsterdam: Von 

Holkema, 1755 pp. 

Gadow H. 1877. Anatomie des Phoenicopterus roseus Pall. und seine Stellung im System. Journal für 

Ornithologie 140: 382–397. 

Garrod AH. 1873. On certain muscles of the the thigh of birds and on their value in classification. 

Part I. Proceedings of the Zoological Society, London 1873: 626–644. 

Garrod AH. 1874. On certain muscles of the the thigh of birds and on their value in classification. 

Part II. Proceedings of the Zoological Society, London 1874: 111–124. 

Glenny FH, Friedmann H. 1954. Reduction of the clavicles in the Mesoenatidae, with some remarks 

concerning the relationship of the clavicle to flight-function in birds. Ohio Journal of Science 54: 

11–113. 

Harrison CJO, Walker CA. 1976. Birds of the British Upper Eocene. Zoological Journal of the Linnean 

Society 59: 323–351. 

Hofer H. 1945. Untersuchungen über den Bau des Vogelschädels, besonderes über den der Spechte 

und Steisshühner. Zoologische Jahrbücher, Abteilung für Anatomie und Ontogenie der Tiere 83: 1–158. 

Holman JA. 1964. Osteology of gallinaceous birds. Quarterly Journal of the Florida Academy of Sciences 27: 

230–252. 

Houde PW. 1988. Paleognathous birds from the early Tertiary of the Northern Hemisphere. Publications 

of the Nuttall ornithological club 22: 1–148.


Howard H. 1955. A new wading bird from the Eocene of Patagonia. American Museum Novitates 1710: 

1–25. 

Huxley TH. 1867. On the classification of birds and on the taxonomic value of the modifications of 

certain of the cranial bones observable in that class. Proceedings of the Zoological Society, London 1867: 

415–472. 

Huxley TH. 1868. On the classification and distribution of the Alectoromorphae amd Heteromorphae. 

Proceedings of the Zoology Society, London 1868: 294–319. 

Johnsgard P. 1967. Observations on the behaviour and relationships of the white-backed duck and 

the stiff-tailed ducks. Wildfowl Trust 18th Annual Report 1965–66: 98–107. 

Kahl MP. 1970. East Africa’s majestic flamingos. National Geographic 137: 276–294. 

Kessler M. 1841. Osteologie der Volgelfüsse. Bulletin de la Société Impériale des naturalistes IV: 467–678. 

Kurochkin EN. 1995a. Synopsis of Mesozoic birds and early evolution of Class Aves. Archaeopteryx 

13: 47–66. 

Kurochkin EN. 1995b. Morphological differentiation of the palaeognathous and the neognathous 

birds. Courier Forschungsinstitut Senckenberg 181: 87–96. 

Lebedinsky NG. 1920. Beiträge zur Morphologie und Entwicklungsgeschichte des Unterkiefers der 

Vögel. Verhandlungen der Naturforschenden Gesellschaft in Basel 31: 39–112. 

Livezey BC. 1986. A phylogenetic analysis of recent anseriform genera using morphological characters. 

Auk 103: 737–754. 

Lowe PR. 1916a. Studies on the Charadriiformes. III. Notes in relation to the systematic position of 

the sheath-bills (Chionididae). Ibis 58: 122–155. 

Lowe PR. 1916b. Studies on the Charadriiformes. IV. An additional note on the sheath-bills: some 

point in the osteology of the skull of an embryo of Chionarchus ‘minor’ from Kerhuelen. V. Some 

notes on the crab-plover (Dromas ardeola Paykull). Ibis 58: 313–337. 

Lowe PR. 1925. On the systematic position of the Jacanidae ( Jacanás) with some notes on a hitherto 

unconsidered anatomical character of apparent taxonomic value. Ibis 67: 132–147. 

Lowe PR. 1926. More notes on the quadrate as a factor in avian classification. Ibis 68: 152–188. 

Maddison WP, Maddison DR. 1992. MacClade. Analysis of Phylogeny and Character Evolution. Version 3. 

Sunderland, Massachusetts: Sinauer Associates, 398 pp. 

Maillard J. 1948. Recherches embryologiques sur Catharacta skua Brünn. Revue suisse Zool 55: 1–144. 

Martin LD. 1987. The beginning of the modern avian radiation. Documents des Laboratories de Géologie 

Lyon 99: 9–19. 

McDowell S. 1978. Homology mapping of the primitive archosaurian reptile palate on the palate of 

birds. Evolutionary Theory 4: 81–94. 

Noriega JI, Tambussi CP. 1995. A Late Cretaceous Presbyornithidae (Aves: Anseriformes) from 

Vega Island, Antarctic Peninsula: paleobiogeographic implications. Ameghiniana 32: 57–61. 

Olson SL. 1978. Multiple origins of the Ciconiiformes. Proceedings of the Colonial Waterbird Group, 

165–170. 

Olson SL. 1985. The fossil record of birds. In: Farner DS, King JR, Parkes KC, eds. Avian Biology 8: 

79–238. 

Olson SL, Feduccia A. 1980a. Relationships and evolution of flamingos (Aves: Phoenicopteridae). 

Smithsonian Contributions to Zoology 316: 1–73. 

Olson SL, Feduccia A. 1980b. Presbyornis and the origin of the Anseriformes (Aves: Charadriomorphae). 


Olson SL, Parris DC. 1987. The Cretaceous birds of New Jersey. Smithsonian Contributions to Paleobiology 

63: 1–22. 

Olson SL, Steadman DW. 1981. The relationships of the Pedionomidae (Aves: Charadriiformes). 


Parkes KC, Clark GA. 1966. An additional character linking ratites and tinamous and an 

interpretation of their monophyly. Condor 68: 459–471. 

Peters DS. 1987. Juncitarsus merkeli n.sp. stütz die Ableitung der Flamingos von Regenpfeifervögeln 

(Aves: Charadriiformes: Phoenicopteridae). Courier Forschungsinstitut Senckenberg 97: 141–155. 

Raikow JR. 1971. The osteology and taxonomic position of the White-backed Duck, Thalassornis 

leuconotus. Wilson Bulletin 83: 270–277. 

Raikow RJ. 1981. Special review. Old birds and new ideas: progress and controversy in paleornithology. 

Wilson Bulletin 93: 407–412. 

Reichenow A. 1882. Die Vögel der Zoologischen Gärten. Vol. 1. Leipzig: L.A. Kittler, 278 pp. 

Seebohm H. 1888. The geographical distribution of the family Charadriidae, or the plovers, sandpipers, snipes, and 

their allies. London: H. Southaran and Co., 524 pp.

482 


Seebohm H. 1889. An attempt to diagnose the suborder of the ancient ardeino-anserine assemblage 

of birds by aid of osteological characters along. Ibis 31: 92–104. 

Seebohm H. 1895. Classification of bitds: an attempt to diagnose the subclasses, orders, suborders, and families of 

existing birds. Supplement. London: R.H. Porter, 1–28. 

Selstam G, Selstam E. 1973. Artbestämning av bröstben samt typbestämning av överarmsben och bäckenben hos 

svenska fa ˚ glar. Stockholm: Fätlbiologerna. 100 pp. 

Shufeldt RW. 1900. Osteology of the Herodiones. Annals of the Carnegie Museum 1: 158–249. 

Shufeldt RW. 1901. On the osteology and systematic position of the screamers (Palamedae: Chauna). 

American Naturalist 35: 455–461. 

Sibley CG, Ahlquist JE. 1981. The phylogeny and classification of ratite birds as indicated by DNA- 

DNA hybridization. In: Scudder GGE, Reveal JL, eds. Evolution Today, Proceedings of the Second 

International Congress of Systematic and Evolutionary Biology. Pittsburgh, Pennsylvania: Hunt Inst. for 

Botanical Documentation, 301–335. 

Sibley CG, Ahlquist JE. 1990. Phylogeny and classification of birds—a study in molecular evolution. New 

Haven, London: Yale University Press, 976 pp. 

Simonetta AM. 1963. Cinesi e morphologia del cranio negli uccelli non passerformi: Studio su varie 

tendenze evolutive, parte 1. Archivio Zoologico Italiano 48: 53–135. 

Stolpe M. 1932. Physiologisch-anatomische Untersuchungen über die hintere Extremität der Vögel. 

Journal für Ornithologie 80: 161–247. 

Storer RW. 1982. Fused thoracic vertebrae in birds: their occurrence and possible significance. Journal 

of the Yamashina Institute of Ornithology 14: 86–95. 

Strauch JG Jr. 1976. The cladistic relationships of the Charadriiformes. Unpublished, Ph.D. Diss., 

University of Michigan, Ann Arbor, Michigan. 

Strauch JG Jr. 1978. The phylogeny of the Charadriiformes (Aves): a new estimate using the method 

of character compatibility analysis. Transactions of the Zoological Society of London 34: 263–345. 

Stresemann E. 1934. Aves. In: Kükenthal W, Krumbach T, eds. Handbuch der Zoologie vol. 7 part 2. 

Berlin: Walter de Gruyter, 899 pp. 

Thulborn RA. 1984. The avian relationships of Archaeopteryx and the origin of birds. Zoological Journal 

of Linnean Society 82: 119–158. 

Vanden Berge JC. 1979. Myologia. In: Baumel JJ, King AS, Lucas AM, Breazile JE, Evans HE, 

eds. Nomina Anatomica Avium. New York: Academic Press, 175–219. 

Verheyen R. 1953. Bijdrage tot de osteologie en die systematiek der Anseriformes. Le Gerfaut 43 

(Suppl.): 373–497. 

Walker CA. 1981. New subclass of birds from the Cretaceous of South America. Nature (London) 292: 

51–53. 

Weber E. 1993. Zur Evolution basicranialer Gelenke bei Vögeln, inbesondere bei Hühner- und 

Entenvögen (Galloanseres). Zeitschrift für zoologische Systematik- und Evolutionsforschung 31: 300–317. 

Wetmore A. 1926. Fossil birds from the Green River deposits of eastern Utah. Annals of the Carnegie 

Museum 16: 391–402. 

Wetmore A. 1960. A classification for the birds of the world. Smithsonian Miscellaneous Collections 139: 

1–37. 

Woolfenden GE. 1961. Postcranial osteology of the waterfowl. Bulletin of Florida State Museum 6: 

1–129. 

Zusi RL. 1984. A functional and evolutionary analysis of rhynchokinesis in birds. Smithsonian Contributions 

to Zoology 395: 1–40. 

Zusi RL, Jehl JR Jr. 1970. The systematic relationships of Aechmorhynchus, Prosobonia and Phegornis 

(Charadriiformes; Charadrii). Auk 87: 760–780. 

APPENDIX 

Essentially all specimens of the listed families in the collection of the National Museum of Natural 

History (USNM) have been studied in order to assess intra-familial variation. Additional specimens of 

families poorly represented at USNM have been studied in the collections of the American Museum 

of Natural History (AMNH) and the Swedish Museum of Natural History (NRM). In the last case all 

specimens have been listed, while for families well-represented at the USNM only reference specimens 

which possess the character states assigned to the family, are listed.


Order Rheiformes 

Rheidae: Pterocnemia pennata USNM 288184 

Order Tinamiformes 

Tinamidae: Rhynchotus rufescens USNM 612020, Tinamus major USNM 562520 

Order Ciconiiformes 

Ardeidae: Ardea purpurea USNM 605008, Cochlearius cochlearius USNM 612615 

Baleanicipitidae: Baleaniceps rex USNM 344963, 345070 

Scopidae: Scopus umbretta USNM 18898 

Ciconiidae: Ciconia ciconia USNM 605018, Leptoptilos crumeniferus USNM 489396 

Threskiornithidae: Geronticus eremita USNM 560147, Ajaia ajaja USNM 491418 

Phoenicopteridae: Phoeniconaias minor USNM 488729, Phoenicopterus roseus USNM 558422 

Order Anseriformes 

Anhimidae: Anhima cornuta USNM 226166, Chauna torquata USNM 428074 

Anseranatidae: Anseranas semipalmata USNM 347638, AMNH 1772, 1837, 2771, NRM 926235, 

926252 

Anatidae: Dendrocygna autumnalis USNM 344997, Stictonetta naevosa USNM 555593, Malacorhynchus 

membranaceus USNM 553596, Anser albifrons USNM 489350, Anas penelope USNM 432293, Mergus 

cucullatus USNM 560992 

Order Galliformes 

Megapodiidae: Megapodius freycinet USNM 560650, Eulipoa wallacei USNM 558275, Macrocephalon 

maleo USNM 225130 

Cracidae: Crax alector USNM 559322, Ortalis garrula USNM 430180, Penelope purpurascens USNM 

428667 

Phasianidae: Chrysolophus amherstiae USNM 322022, Agriocharis ocellata USNM 347792 

Order Gruiformes 

Mesitornithidae: Monias benschi USNM 290927 

Gruidae: Grus canadensis USNM 431924, Balearica pavonina USNM 345685 

Aramidae: Aramus scolopaceus USNM 227688, Aramus guarauna USNM 501021 

Psophiidae: Psophia crepitans USNM 321843, Psophia leucoptera USNM 500623 

Rallidae: Rallus longirostris USNM 556832, Porphyrio pulverulentus USNM 226035, Notornis mantelli 

USNM 612797 

Heliornithidae: Heliornis fulica USNM 345807 

Rhynochetidae: Rhynochetus jubatus USNM 612087, AMNH 554, 1326, 3932 

Eurypygidae: Eurypygas helias USNM 492379, AMNH 3750 

Cariamidae: Cariama cristata USNM 612030, Chunga burmeisteri USNM 431487 

Otididae: Lissotis melanogaster USNM 490229 

Order Charadriiformes 

Pedionomidae: Pedionomus torquatus USNM 555614 

Jacanidae: Jacana spinosa USNM 562496 

Rostratulidae: Rostratula benghalensis USNM 559818 

Dromadidae: Dromas ardeola USNM 321489 

Haematopodidae: Haematopus ostralegus USNM 502440, 502679 

Ibidorhynchidae: Ibidorhyncha struthersii USNM 292767 

Recurvirostridae: Recurvirostra americana USNM 561365, Cladorhynchus leucocephalus USNM 554595 

Burhinidae: Burhinus capensis USNM 558484 

Glareolidae: Cursorius cursor USNM 603504 

Charadriidae: Vanellus senegallus USNM 558496 

Scolopacidae: Numenius phaeopus USNM 499330 

Thinocoridae: Attagis malouinus USNM 490853 

Chionididae: Chionis alba USNM 488297, AMNH 549, 8849, 9275 

Stercorariidae: Catharacta maccormicki USNM 491325 

Laridae: Larus ridibundus USNM 610490 

Rynchopidae: Rynchops niger USNM 490746 

Alcidae: Uria aalge USNM 559410 

Order Incertae Sedis: 

Opisthocomidae: Opisthocomus hoazin USNM 344065, 431012, 612024, AMNH 1177, 3006, 12127

Systematic relationships of the palaeogene family Presbyornithidae ...

Create successful ePaper yourself

Delete template?

Save as template?