An Updated Classification of the Recent Crustacea

logeny and taxonomy. This focus on ‘‘. . . animals
that work . . .’’ is directly lifted from the later writings
of Sidnie Manton. Schram (1993, The British
School: Calman, Canon, and Manton and their effect
on carcinology in the English speaking world;
Crustacean Issues 8:321–348) outlined the roots of
Mantonian reasoning in an idealist philosophical
tradition that passed on through Thompson and his
treatise On Growth and Form. This is essentially a
Platonic view of comparative biology, and stands
essentially at odds with the current emphasis, either
a priori or a posteriori, on elucidating ground
plans. You are of course free to quote Fryer, but
you ought to give fair play to alternative philosophical
and conceptual foundations for systematics.
Submitted by Frederick R. Schram,
Zoölogisches Museum, Amsterdam
BRANCHIOPODA: ANOSTRACA
Weekers et al. (in press) examined small subunit
ribosomal DNA of anostracans from 23 genera belonging
to eight of the nine families recognized by
Brtek (1997). Their results do not support the family
Linderiellidae or Polyartemiidae. Instead, they
group Linderiella with Polyartemia and Polyartemiella
as a subfamily of the family Chirocephalidae.
Morphological considerations support this arrangement
in that the three genera share rigid antennal
appendages on otherwise simple antennae and double
pre-epipodites. Unfortunately, these workers
were not able to obtain usable Artemiopsis. Thus,
the validity of Artemiopsidae remains untested by
molecular methods; however, I continue to consider
that the morphology of the penes places Artemiopsis
in the family Chirocephalidae.
Additional References
Weekers, P. H. H., G. Murugan, J. R. Vanfleteren, and H.
J. Dumont. In press. Phylogenetic analysis of anostracans
(Branchiopoda: Anostraca) inferred from
SSU rDNA sequences. Molecular Phylogenetics and
Evolution.
Submitted by Denton Belk,
Our Lady of the Lake University,
San Antonio, Texas
REMIPEDIA
See comments from G. Boxshall under Maxillopoda
and from M. Christoffersen under Crustacea.
REMIPEDIA
In the section about the Remipedia, you mention
that the similarities between the Maxillopoda and
the Remipedia are symplesiomorphies. But what
are these? The only similarities I can think of, I
would not consider as symplesiomorphies, but perhaps
as convergences. Perhaps it is unwise to mention
something like this without also mentioning
the characters. The first question people will raise
is what these characters are. In the same section
you use the term ‘basal’ about branchiopods, but
what does that actually mean? There are two possibilities,
either early off split (e.g., sister group) or
primitive (or at least with many primitive features),
but these are two different things, as addressed earlier.
Submitted by Jørgen Olesen,
University of Copenhagen, Denmark
CEPHALOCARIDA
In the section about the Cephalocarida, you say
that the sequence of the classes reflects something
(it doesn’t matter exactly what in this context). My
problem here is that I don’t think that the sequence
of taxa of equal rank in a classification reflects anything.
If a classification shall reflect anything concerning
relationship, it has to be put into the hierachical
categories (like you have done for the classification
within the Branchiopoda, for example). I
think this is an old way of thinking with no meaning
today.
Submitted by Jørgen Olesen,
University of Copenhagen, Denmark
MAXILLOPODA
The status of the Maxillopoda remains uncertain. I
consider that there is a group of related taxa which
form the core of a Maxillopoda: these are the Copepoda,
Thecostraca, Tantulocarida and Ostracoda
(excluding the Phosphatocopines which are not ostracods
and do not even belong to the crown group
of the Crustacea). The Mystacocarida and Branchiura
may also belong to this group but the available
supporting evidence is weaker. I also consider
that the Remipedia is related to the maxillopodan
lineage. Remipedes share several derived features of
the thoracopods, maxillules and maxillae with other
maxillopodans as indicated in my paper on comparative
musculature (Boxshall, 1997).
Additional References
Boxshall, G. A. 1997. Comparative limb morphology in
major arthropod groups: the coxa-basis joint in postmandibular
limbs. In Arthropod relationships, eds.
R. A. Fortey and R. H. Thomas, 155–167. London:
Chapman and Hall.
Submitted by Geoff Boxshall,
Natural History Museum, London
MAXILLOPODA
I really understand your difficulties here. To cut the
message short, I think you should have chosen to
include the component taxa of the Maxillopoda as
classes and then skip the ‘Maxillopoda’ (as you also
almost decided to, I can see from your writing).
I know you [are trying] to be conservative by
following Bowman and Abele here, but actually, to
be real conservative you should skip that level. This
Contributions in Science, Number 39 Appendix I: Comments and Opinions 105