An Updated Classification of the Recent Crustacea

ine isopods that has been posted on the World
Wide Web by B. Kensley and M. Schotte (http://
www.nmnh.si.edu/iz/isopod). However, in that
compilation, the various suborders and their constituent
superfamilies and families are arranged alphabetically.
Brusca and Wilson (1991), while proposing
some phylogenetic changes that would seriously
alter the arrangement of groups as presented
here (and at the same time countering several of
the hypotheses forwarded earlier by Wägele, 1989),
stopped short of proposing a new classification
based on their hypothesis. Their feeling was that
insufficient evidence had been amassed for proposing
classifications based on the phylogenetic hypotheses
they were presenting as testable ideas. The
Brusca and Wilson (1991) analysis was criticized
by Wägele (1994), who in fact used their paper to
point out potential pitfalls in any attempt at computer-generated
cladistic analyses. Wägele (1994)
was in turn rebutted by Wilson (1996), who was
answered by Wägele (1996), and it would seem
that we have a long way to go before any consensus
concerning isopod phylogeny (not to mention phylogenetic
method) is reached. Thus, our classification
is in some ways a step backward in that we
continue to recognize some groups, such as the Flabellifera,
that appear clearly paraphyletic (following
the analyses of both Brusca and Wilson, 1991,
and Wägele, 1989) but for which no alternative
classifications have been proposed. In the most recent
overall treatment of isopods, Roman and Dalens
(1999) continue to recognize the Flabellifera as
well while acknowledging that it is a heterogeneous
assemblage.
Additionally, many changes, especially those concerning
names and dates of the authorities credited
with establishing families but also concerning
whether or not to recognize a particular family,
have been incorporated at the request of some of
the major workers (e.g., L. Holthuis, B. Kensley, R.
Brusca, G. Poore, W. Wägele, and G. Wilson) via
personal communications. It has not always been
possible for us to verify these suggestions. Often,
despite a rather large library on crustacean systematics
at our disposal, we have been unable to see
the original references. In cases where we received
conflicting information (such as whether the family
Arcturidae should be credited to White, 1850 vs.
Bate and Westwood, 1868 vs. Sars, 1899) and/or
we could not verify by checking on all of the suggested
references ourselves, we have chosen the first
known usage (in this case, using Arcturidae White,
1850, which turns out to be correct according to
G. Poore, who owns the book) in accordance with
ICZN article 50.3.1. One such change involves the
establishment of a large number of families and superfamilies
credited to Latreille. L. Holthuis (pers.
comm.) assures us that 1802 is the correct date for
the many taxa that have been, in the past, credited
to Latrielle (1803) (see earlier section on names,
dates, and the ICZN).
Major papers suggesting changes in how we or-
ganize the Isopoda that have appeared subsequent
to Bowman and Abele (1982) include Wägele
(1989) and Brusca and Wilson (1991). Poore
(2001a) presented a phylogeny of the Anthuridea
suggesting relationships among the six families
(two new), but to our knowledge, there have not
as yet been names proposed for the divisions suggested
by him. The most recent review, by Roman
and Dalens (1999), recognizes eight suborders.
Their arrangement differs from ours in that (1) they
recognize the suborder Gnathiidea, which we do
not, and (2) they do not recognize the suborders
Microcerberidea and Calabozoidea, which we do,
for reasons discussed below.
Concerning the former suborder Gnathiidea,
Brusca and Wilson (1991) suggested that the gnathiids
were derived from among the families traditionally
thought of as ‘‘flabelliferan’’ isopods (a
group that they demonstrate is not monophyletic).
Wägele (1989, pers. comm.) also would remove the
gnathiids from their own suborder, but his preference
was to place them among the Cymothoida, a
group he recognizes as containing a large number
of former Flabellifera families. We have, for the
current classification, removed the gnathiids from
their own superfamily and have placed them within
the Flabellifera, knowing that the Flabellifera itself
is not monophyletic and must some day be extensively
revised. L. Holthuis (pers. comm.) has suggested
that we credit the family name Gnathiidae
to Leach (1814) rather than to Harger (1880), as
was used by Bowman and Abele (1982) and Roman
and Dalens (1999).
SUBORDER PHREATOICIDEA
Wilson (pers. comm.) suggests that many of the
subfamilies of the Amphisopodidae recognized by
Nicholls (1943, 1944) will need to be elevated to
family level (e.g., as Hypsimetopodidae, Mesamphisopodidae,
Phreatoicopsididae) once this suborder
is revised (see also Wilson and Johnson,
1999; Wilson and Keable, 1999, 2001). Our classification
follows Roman and Dalens (1999) in recognizing
three families (the same three that appear
in Bowman and Abele, 1982). By listing the phreatoicids
first among all isopod suborders, we are acknowledging
the primitive nature of these isopods.
Brusca and Wilson (1991) and Wilson and Johnson
(1999) have indicated that the phreatoicideans, all
of which are restricted to Gondwanan fresh waters,
may be ‘‘the earliest derived isopod Crustaca’’ (Wilson
and Johnson, 1999:264). The phreatoicidean
fossil record extends back to the Carboniferous
(Wilson and Johnson, 1999).
SUBORDER ANTHURIDEA
Within this suborder, the family Antheluridae was
described by Poore and Lew Ton (1988) and the
families Expanathuridae and Leptanthuridae were
described recently by Poore (2001a; see also Poore,
1998). Our treatment differs from that of Roman
38 � Contributions in Science, Number 39 Rationale