An Updated Classification of the Recent Crustacea

Thus, he did recognize (temporarily, at various
times) Talitroidea Bulycheva, 1957, Corophioidea
Barnard, 1973, and Haustorioidea Barnard and
Drummond, 1982. Several of Jerry’s informal ‘‘anglicized’’
groupings of freshwater families (e.g.,
‘‘gammarida,’’ ‘‘crangonyctoids,’’ ‘‘hadzioid
group,’’ etc., in Barnard and Barnard, 1983; Williams
and Barnard, 1988) rather closely resemble
some of the superfamilies (and families) formally
named and fully defined previously (1973, 1977,
1979, 1982) by Bousfield and co-workers (e.g.,
about 75% compatibility with Gammaroidea, Hadzioidea,
Crangonyctoidea, Melphidippoidea, etc.).
However, he did not attempt formal phyletic groupings
of most marine gammaridean families, nor formal
integration with other amphipod suborders.
Unlike Sars (1895), Stebbing (1906), and other
‘‘turn-of-the-century’’ workers, Jerry apparently did
not recognize the significance of reproductive form
and behaviour in amphipod phylogeny. Jerry’s final
major work (with Gordan Karaman, 1991, p. 7)
disavowed the significance or use of the formal superfamily
concept, and listed families alphabetically
rather than phyletically or semi-phyletically (as in
Sars and Stebbing, above). Some classifications are
based on carefully defined characters and character
states that have required (and will continue to require)
modification according to features found in
subsequently discovered species and genera, and
are consistent at proper classificatory levels. The
cladistic arrangement by Kim and Kim (1993), reviewed
rather unfavourably by Schram (1994), underscores
the unreliability of cladistic analysis when
care is not taken in the appropriate selection and
accurate definition of characters and character
states.
[Concerning your statement about Bousfield and
Shih], Bousfield and Shih (1994) represents an updating
and refinement of previous 20 years of
study and publication on gammaridean phylogeny.
[Concerning your statement about Reptantia],
‘‘Natantia’’ and ‘‘Reptantia’’ are terms (names)
pragmatically defined, but not incorporated formally
by Bousfield and Shih (1994). The terms are
analogous to former groupings of families and superfamilies,
etc., within the Order Decapoda.
[Concerning your statement about names and
dates], omission of author names and dates in tabular
listing of families and superfamilies is modeled
after similar ‘‘heading’’ omissions in Barnard’s
‘‘Families and Genera . . .‘‘ (1969) and earlier ‘‘Index
. . .’’ (1958). Obviously, these names are fully
treated in the major references (e.g., Stebbing,
1906; Gurjanova, 1951; Bousfield 1979, 1982,
l983; Schram, 1986). Readers are expected to provide
something of substance to the discussion, such
as commentary on the paper’s extensive analysis of
‘‘across-the-phyletic-board’’ variability of major
characters and character states (antennae to telson)
that would be of prime significance in a cladistic
treatment.
[Concerning your statement to the effect that we
presented different phylogenetic hypotheses in our
1994 paper], Bousfield and Shih acknowledge
(problems in resolution) that they do not have a
‘‘final answer’’ to the probably correct evolutionary
history of the Amphipoda (only one answer can be
correct!). Their ‘‘semi-phyletic’’ methodology modifies
the strictly phenetic format of Sneath and Sokal
(1973) by careful ordering of character states
to arrive at a ‘‘plesio-apo-morphic index’’ of probably
correct phyletic relativity for each taxon. This
approach tends to minimize the negative effects of
homoplasious convergence in many of these character
states (analyzed above). Mike Ghiselin (1984)
correctly points out, rigid and uncritical application
of cladistic methodology alone quite frequently
leads the user to a less-than-credible phylogenetic
result. Thus, use of the ‘‘Wagner 78’’ cladistic program
often provides multiple ‘‘trees’’ from the same
data base, each one different, each one tending to
invalidate the other, and none probably correct!
[Concerning your statement about cladistic analyses
having high priority], to my knowledge, cladistic
‘‘purists’’ have not yet actually demonstrated
a cladistically derived treatment of all 118 gammaridean
families of your list. Chances of doing so
would appear ‘‘slim-to-non-existent.’’ Instead, advocacy
of rDNA methodology would probably result
much sooner in a most-probably-correct answer!
[Concerning your statement that most workers
would prefer to see the families listed alphabetically
rather than by superfamily], how surprising that
such an unsupported statement should come from
Les Watling, a confirmed crustacean phylogenist!
On more serious reflection, Les may find that quite
a few current workers (e.g., Mike Thurston, John
Holsinger) do not ‘‘give up’’ so easily on the full
solution of this difficult problem.
[Concerning your use of the word hypotheses],
do you mean ‘‘concepts’’? All family and superfamily
names represent ‘‘concepts’’ of presumed natural
groupings of species. Some are better defined (in
terms of careful definition of character states) and
longer time-tested than others. Most superfamily
names in Bousfield and Shih (1994) have been carefully
and fully (multiple-character) defined, their
component families named, and time-tested (by
other workers as well) over a 15 year period.
Since superfamily taxonomic stability (75%) would
appear at least equal to that of the component family-level
names of the current Martin–Davis list, although
both lists are ‘‘conceptual,’’ neither can realistically
be termed ‘‘hypothetical.’’
Additional References
[Note: Dr. Bousfield did not supply references to all papers
mentioned above.]
Bousfield, E. L. 1995. A contribution to the natural classification
of Lower and Middle Cambrian arthropods:
food gathering and feeding mechanisms. Amphipacifica
II(1):3–34.
108 Contributions in Science, Number 39 Appendix I: Comments and Opinions