An Updated Classification of the Recent Crustacea

for a rebuttal of Dahl’s criticism). Inclusion of leptostracans
within the Malacostraca has been further
supported by molecular evidence (rDNA data
summarized in Spears and Abele, 1997, 1999; see
also Shultz and Regier, 2000, for EF-1 and Pol II
data). Hessler (1984) established the family Nebaliopsidae
in recognition of the great differences setting
the genus Nebaliopsis apart from other leptostracans,
thereby doubling the number of recognized
families of the extant phyllocarids. However, J.
Olesen (1999b, and pers. comm.) finds that, depending
upon the choice of outgroups (and characters)
used in cladistic analyses of the group (based
on descriptions in the literature), there is still some
room for doubt as to whether Nebaliidae is monophyletic
or paraphyletic (with Nebaliopsis nested
within the other nebaliacean genera). Most recently,
Walker-Smith and Poore (2001) have erected a
third family, Paranebaliidae, to contain the genera
Paranebalia and Levinebalia (the latter of which
was described by Walker-Smith, 2000).
Our treatment of the Phyllocarida follows Hessler
(1984), Martin et al. (1996), Dahl and Wägele
(1996), and our PEET web page for Leptostraca
(URL http://www.nhm.org/peet/) in recognizing
two extant families (see Rolfe, 1981, for extinct
phyllocarids) plus the recently established family
Paranebaliidae following Walker-Smith and Poore
(2001). Most authors in the past have credited the
family Nebaliidae to Baird (1850). However, according
to L. Holthuis (pers. comm.), Samouelle
(1819:100) mentioned ‘‘Fam. VI. Nebaliadae’’ [sic]
in his ‘‘Entomologist’s Useful Compendium,’’ which
of course predates Baird’s (1850) work. Thus, we
have attributed the family Nebaliidae to Samouelle,
1819.
SUBCLASS HOPLOCARIDA, ORDER
STOMATOPODA
Several workers, today and in the past (examples
include Hessler, 1983; Scholtz, 1995; Richter and
Scholtz, in press), have considered the hoplocarids
to be members of the Eumalacostraca, a placement
that has been used often and in some textbooks as
well (e.g., Brusca and Brusca, 1990). However, we
have retained their placement as a separate subclass
within the Malacostraca pending further exploration
of this question (see review by Watling et al.,
2000). Our treatment of the hoplocarids as separate
from the other Eumalacostraca also is consistent
with some (admittedly weak) molecular evidence
(see Spears and Abele, 1997, 1999b) and
with cladistic analyses based mostly on fossil taxa
(e.g., Hof, 1998a, b; Hof and Schram, 1999).
Schram (1971, 1986) had argued earlier for separate
status of the hoplocarids as well. Spears and
Abele (1997) could state only that the position of
the ‘‘Hoplocarida relative to the Eumalacostraca is
equivocal’’ (low bootstrap value) based on rDNA
sequence data, and thus they were ‘‘unable to determine
whether hoplocarids represent a separate,
independent malacostracan lineage with taxonomic
rank (subclass) equivalent to that of phyllocarids
and eumalacostracans.’’ Their subsequent paper
(Spears and Abele, 1999b) seems (to us) to indicate
somewhat stronger evidence that hoplocarids are
not eumalacostracans, but the authors are suitably
cautious in not saying so. Without firm indications
that we should do otherwise, we have maintained
separate status for the Hoplocarida and Eumalacostraca.
Although a thorough cladistic analysis of
fossil and extant crustacean taxa by Schram and
Hof (1998) resulted in a tree that showed hoplocarids
arising from somewhere within the Eumalacostraca,
these authors also noted that forcing the
hoplocarids into a ‘‘sister group’’ position to the
Eumalacostraca increased tree length by only 1%.
Other workers (e.g., Watling, 1999a), recognizing
how very derived the stomatopods are, place them
in the Eumalacostraca as the sister taxon to the Eucarida.
Most recently, Richter and Scholtz (in press)
suggested that hoplocarids occupy a basal position
within the Eumalacostraca. Thus, placement of the
hoplocarids continues to be an unresolved issue,
but we felt that the weight of the evidence placed
them outside, rather than within, the Eumalacostraca.
Scholtz (pers. comm.) additionally suggests
that our crediting the name Eumalacostraca to
Grobben is therefore incorrect, as Grobben included
the hoplocarids among the Eumalacostraca (but
see earlier notes on names, dates, and the ICZN).
Within the Hoplocarida, most of our changes are
based on the catalog provided by H.-G. Müller
(1994) and on Manning (1995), and our final arrangement
of families and superfamilies follows the
recent cladistic analysis by Ahyong and Harling
(2000). Publications that describe or recognize families
or higher taxa of stomatopods subsequent to
Bowman and Abele (1982) include Manning (1995,
Indosquillidae, Parasquillidae, Heterosquillidae),
Manning and Bruce (1984, Erythrosquillidae [for
which the superfamily Erythrosquilloidea was later
created by Manning and Camp, 1993]), Manning
and Camp (1993, Tetrasquillidae), Moosa (1991,
Alainosquillidae), and Ahyong and Harling (2000,
superfamilies Eurysquilloidea and Parasquilloidea).
Concerning phylogeny within the Hoplocarida,
there is recent evidence from several laboratories
that the superfamily Gonodactyloidea as presented
in Bowman and Abele (1982) is not a monophyletic
grouping (Hof, 1998b; Ahyong, 1997; Barber and
Erdmann, 2000; Ahyong and Harling, 2000; Cappola
and Manning, 1998; Cappola, 1999) and that
within the gonodactyloids the eurysquillids may be
paraphyletic. These same authors disagree over
whether the Bathysquilloidea are monophyletic
(Cappola and Manning, 1998) or not (Ahyong,
1997). A comparative study of eye design in stomatopods
(Harling, 2000) also supports a nonmonophyletic
Gonodactyloidea and questions the fivesuperfamily
scheme of Müller (1994). The nonmonophyly
of the Gonodactyloidea necessitates the
creation of additional families and superfamilies to
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