An Updated Classification of the Recent Crustacea

subfamilies of the Cryptoniscidae, for which Bowman
and Abele (1982), followed by Schram (1986),
used the name Liriopsidae (see Grygier and Bowman,
1990). Crediting authorship of the family
Cryptoniscidae (and thus Cryptoniscoidea) to Kossman
rather than to Gerstaecker is based on the correction
published by Grygier and Bowman (1991).
Following Trilles (1999), we also do not recognize
the family Microniscidae Müller for the genus Microniscus,
although this family is still listed in some
compendia (e.g., by Brasil-Lima, 1998:641, in
Young, 1998). The spelling Cabiropsidae used by
Trilles (1999) and some earlier workers is corrected
to Cabiropidae based on the explanation given by
Sassaman (1992).
SUBORDER ONISCIDEA
The relationships of the terrestrial isopod groups to
one another and to marine relatives are still poorly
understood. Although Schmalfuss (1989, in Ferrara,
1989) proposed some relationships among oniscideans
and compared the classification of oniscideans
presented by Holdich et al. (1984) with a
new one based on his analysis, Schmalfuss’ work
was based on relatively few characters and was criticized
by Brusca (1990). Wägele (pers. comm.) informs
us that there are ‘‘enormous advances that
will be published next year’’ concerning the phylogeny
of the Oniscidea and that several groups
presented here are not monophyletic; further, he informs
us that the ‘‘section’’ Diplochaeta is currently
being revised. Until these advances become known
to us, we are unsure as to what relationships our
classification should suggest. Holdich et al. (1984)
used two infraorders (the Tylidae were placed in a
separate infraorder, Tylomorpha), and within the
infraorder Ligiamorpha they recognized three sections.
Schmalfuss (1989) did not employ the infraorder
level and instead divided all oniscideans
among four major sections. More recent arrangements
of the oniscidean families have been proposed
by Erhard (1995) and Tabacaru and Danielopol
(1996a, b; see also Roman and Dalens, 1999,
who followed mostly Schmalfuss, 1989, and also
Mattern and Schlegel, 2001). Many workers (e.g.,
Souza-Kury, 1998, in Young, 1998) list the oniscidean
families alphabetically.
We have maintained the two-infraorder system
and have not recognized the new section Microchaeta
proposed by Schmalfuss. The four families
Helelidae, Irmaosidae, Pseudarmadillidae, and
Scleropactidae have been removed from any infraorder
or superfamily, as their status is indeterminate
(R. Brusca, pers. comm.). For the currently
accepted family names (as well as authors and
dates, which were not included by Schmalfuss), we
have had to rely primarily on the alphabetical list
of oniscidean families maintained on the Smithsonian’s
server (Kensley et al., 1998; URL http://
www/nmnh.si.edu/iz/isopod), which is based on
Schmalfuss’ families (the terrestrial isopod list is
also accessible via the Kensley et al. list of marine
isopods, URL gopher://nmnhgoph.si.edu:70/11/.
invertebrate/.crustaceans). Users of the terrestrial
isopod list are strongly cautioned by the authors
(Kensley et al., 1998):
This list is thus intended as a rough guide to the astounding
array of names and taxa in the Oniscidea.
Synonymy will be rampant in the list. We have tried to
use the most current interpretations of some genera and
families. Nevertheless, we realise that in no way do we
even begin to resolve the taxonomic confusion that
reigns in this group. There is uncertainty regarding the
familial placement of some genera, and there will certainly
be repetition of the same specific name under
different genera. There are omissions from the list, either
of names of taxa that we’ve completely missed, or
of authors and dates of publication and/or of localities
that we have been unable to find.
We are aware of only two newly described oniscidean
families since 1982: Ferrara and Taiti
(1983) described the family Irmaosidae, and
Schultz (1995) described the Dubioniscidae (see
Souza-Kury, in Young, 1998:656). Establishment of
the family Platyarthridae is credited to Verhoeff
(rather than to Vandel) by Ferrara and Taiti (1989),
who also note that the families Bathytropidae and
the Platyarthridae might coincide. G. Poore (pers.
comm.) notes that the Styloniscidae Vandel, 1952,
is a replacement name for the Patagoniscidae Verhoeff,
1939, and is conserved under ICZN article
40; he therefore recommends that the earlier date
appear in parentheses, as Styloniscidae Vandel,
1952 (1939). Characters that define the various
groupings of the oniscideans are given by Roman
and Dalens (1999), although workers should note
that the characters and groupings based on them
are, in some cases, not universally accepted. A recent
molecular analysis (Mattern and Schlegel,
2001) based on ssu rDNA suggests that Crinochaeta
and Synochaeta are monophyletic, and that these
groups together are the sister taxon to the Diplochaeta.
ORDER TANAIDACEA
Many of the major taxonomic changes suggested
by the late J. Sieg were made prior to 1982 and
were therefore incorporated into the Bowman and
Abele classification. Subsequent to 1982, there were
also some large-scale rearrangements suggested by
Sieg (1983a, b, 1984, 1986a, b), but there has been
almost no work done at higher levels of tanaid systematics
since that time. Unfortunately, it now appears
that many of the characters established or
used by Sieg do not hold up well under scrutiny
(see Larsen and Wilson, 1998), and it is not clear
how many of Sieg’s characters or numerous classificatory
assignments will survive. Kim Larsen (pers.
comm.) is actively studying the group and has kindly
updated us, as far as is possible pending a thorough
revision of the group. Additionally, he has
provided us with many suggested changes. An excellent
and comprehensive web site maintained by
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