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----- Original Message -----
Sent: Tuesday, May 15, 2001 1:57 AM
Subject: Re: T-J Extinction event article
(more media errors?)
In a message dated
5/12/01 10:59:39 AM Pacific Daylight Time,
Dinogeorge@aol.com writes:
It seems to me that the most reasonable clade that could be
given the name
Mammalia would be the clade of all amniotes more closely
related to extant
crown-group mammals than to the next closest (i.e.,
the other) amniote
crown-group, which would be "reptilia+aves."
Well, to be perfectly honest, if I had my druthers,
You *have* the possibility, once, when the
PhyloCode is implemented and nobody else has yet defined senior synonyms of
these under the PhyloCode:
I'd recognize six major
stem-based groups ("classes") of tetrapods,
anchored on typical living
representatives:
Batrachopsida
("froggy-looking things"): {_Rana_>_Homo_, _Chelone_, _Vipera_,
_Crocodylus_, _Passer_}. Would currently include frogs, salamanders,
caecilians, etc.
Some have proposed to define Amphibia this way.
But Batrachopsida is a less ambiguous name, IMHO.
Theropsida ("beasty-looking things"): {_Homo_>_Rana_, _Chelone_,
_Vipera_,
_Crocodylus_, _Passer_}. Would currently include mammals,
other therapsids,
"pelycosaurs".
Practically everyone will support that, IMHO,
because Seeley explicitely meant this clade when he named
Theropsida.
Chelonopsida ("turtlish-looking things"): {_Chelone_>_Rana_, _Homo_,
etc.}.
Would include turtles and whatever the heck they're most
closely related to.
Sounds a lot better than Anapsida (which
explicitely refers to a plesiomorphy and thus cries to be
doubly paraphyletic).
Herpetopsida ("snaky-looking things"): {_Vipera_>_Rana_, _Homo_,
etc.}.
Would include snakes, other lizards, tuataras,
etc.
Snaky? Not creepy?
Crocodilopsida ("crocodilish-looking things"): {_Crocodylus_>_Rana_,
_Homo_,
etc.}. Would include crocodilians as well as aetosaurs,
rauisuchians,
phytosaurs, etc. (depending on just where turtles fit in).
Sounds IMHO less abstract than Crurotarsi, which
has practically the same definition
Ornithopsida ("birdy-looking things"): {_Passer_>_Rana_, _Homo_,
etc.}.
Would include birds and other dinosaurs, "lagosuchians", and
perhaps
pterosaurs.
Definitely better than the current name
Ornithosuchia!!!
Other "classes" could (but need not necessarily) be named analogically
for
groups that do not fit into any of the above clades.
There are lots of such (extinct)
groups...
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