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Re: Synapsids are NOT reptiles!



In a message dated 95-12-14 11:17:19 EST, Thomas_R_HOLTZ@umail.umd.edu (th81)
writes:

>[Geez, I don't see to many of the anticladistic faction out there arguing
for
>keeping "Invertebrata", or "Animalia" sensu General Public (all animals but
>humans).  I wonder why?]

I can see uses for a formal taxon Invertebrata, defined as the clade Animalia
minus the clade Chordata. It would, however, probably violate the "rule" of
forming paraphyletic taxa only when the clades removed are considered at the
same Linnaean rank as the taxon being created or higher. If Invertebrata were
to be a subkingdom of Animalia, say, then Chordata would have to be one, too.
Not enough people would be willing to raise Chordata to a subkingdom,
although a decent case could be made for creating a subkingdom out of
Chordata and a few minor near-chordate phyla (there's even a name for this
clade, but it escapes me right now). Likewise, one would have to be willing
to construct an entire kingdom for the single species _Homo sapiens_ before
one could justify removing it from Animalia and making a paraphyletic kingdom
out of it.

Incidentally, collectors of phyla should note a new phylum,Cycliophora, of
Invertebrata defined in the current issue of _Nature_. I haven't seen the
article yet, but I think the phylum contains but a single species thus far.