SPHENOPHRYNE - American Museum of Natural History

4 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 253
ABSTRACT
Parker (1934) distinguished Sphenophryne from other genera of the Genyophryninae
(Sphenophryninae in his work) by its pectoral girdle having a more nearly complete complement
of bony and cartilaginous elements. Otherwise, the species he placed there were a diverse
lot, including ones adapted for climbing, for living in or on leaf litter, or for a cryptic, even
burrowing existence. The characteristics of the pectoral girdle are primitive compared to those
of other genyophrynine genera, which have reduced or lost one or more of the elements. Thus,
the common possession of a primitive girdle is inadequate as the sole character defining the
genus. In the present work I review species with the supposedly diagnostic character of Sphenophryne
and recognize four genera: Sphenophryne (monotypic), and three removed from synonymy—Austrochaperina
(23 species), Liophryne (6 species), and Oxydactyla (5 species). The
characters I use to define the genera are for the most part closely tied to the habits of the
species and thus are subject to the criticism that homoplasy rather than synapomorphy is
demonstrated. Regardless, the probability that the new arrangement identifies four monophyletic
lines is considerably greater than that Sphenophryne, as it has been constituted, is monophyletic.
Sphenophryne, Liophryne, and Oxydactyla are confined to New Guinea. Austrochaperina
has one species on New Britain, four endemic to northern Australia, one shared between
Australia and New Guinea, and 18 on New Guinea and adjacent islands. The genus and species
Microbatrachus pusillus, based on a hatchling from the Aru Islands, are considered unidentifiable.
Of the 35 species recognized, 17 are described as new and one is removed from
synonymy.
In his classic monograph of the Microhylidae,
Parker (1934) recognized the genus
Sphenophryne with 10 species found in Australia
and New Guinea and considered three
genera as synonymous to it. 1 In more than
six decades since, the only taxonomic modification
at the generic level was the synonymization
of Microbatrachus (which Parker
recognized) with Sphenophryne (Tyler,
1978). The number of included species has
risen from 10 to 18, mostly through discovery
of new species (listed in Zweifel, 1985a,
with an additional species in Zweifel,
1985b). Parker’s diagnostic feature of the genus
within the subfamily Sphenophryninae
(Genyophryninae of current authors) was
that the pectoral girdle had a more nearly
complete set of ventral elements than did the
1 Parker (1934: 159) also reported a ‘‘?Sphenophryne
sp.’’ based on embryos ‘‘collected from the pitcher of a
Nepenthes at Kuching [Sarawak],’’ far from the known
range of any genyophrynine microhylid. It is likely that
this extralimital record is based on a rhacophorid, possibly
Philautus, which oviposits in Nepenthes and whose
larvae may metamorphose prior to hatching; see Dring
(1979: 207–208) and Inger and Stuebing (1997: 163).
INTRODUCTION
other genera he recognized 2 : coracoids, clavicles
that extend from the scapula to near the
midline, procoracoid cartilages, and a cartilaginous
sternum.
The set of features described for the pectoral
girdle is unquestionably primitive compared
to the more reduced states in all other
genyophrynine genera and thus cannot diagnose
a monophyletic clade. Species currently
assigned to Sphenophryne on the sole
basis of girdle structure are a diverse lot morphologically
and ecologically, and they include
scansorial, riparian, and terrestrial
forms. The inevitable impression is that they
may not be a monophyletic group. My principal
objective has been to examine the suite
of genyophrynine species with the primitive
pectoral girdle, including several undescribed
and synonymized taxa, in order to see if phylogenetic
sense can be made and a defensible
arrangement can be proposed that does not
depend on shared primitive characters. Additional
objectives were to identify and describe
previously unrecognized species, to
assess the status of names in synonymy, and
2 Oreophryne,
Aphantophryne.
Microbatrachus, Cophixalus, and