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Give us a break




Nick,
I certainly hope you are kidding. Sounds like Crown-group-mania. A separate Class for turtles? And do you know what a caecilian looks like?--- more like a snake or worm than a frog. Do ornithischians look more like birds or beasts (and is a bat more beasty or birdy-looking)? What about ichthyosaurs (neither snaky nor birdy). Not to mention that -opsida is the ending botanists give to metaphyte classes.
There is nothing wrong with four classes of tetrapods (Amphibia, Reptilia, Aves, & Mammalia), except that the first two are paraphyletic with respect to those that follow. And of course, that is the primary sin of cladistic religiosity:
"Thou shall not commit formal paraphyly."
Come hell or high water, confusion, instability, inconvenience, condemned for Ivory Tower snobbery, creating a legalistic, bureaucratic maze, that will even drive cladists crazy. Sacrifice all else, but destroy all the heathen formal paraphyletic groups, and one will earn a place in Cladist Heaven.
Pardon me if some formal paraphyly or impure Latinization offends the purists, but I'll take fewer names, greater utility, relative stability, and a little common sense any day. Thank you Benton, Dodson, Cavalier-Smith, Mayr, and Ashlock. They, most biologists, and the public that support your work, all cry out to the pure cladists:
GIVE US A BREAK.
------- Ken
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Well, to be perfectly honest, if I had my druthers, 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.


Theropsida ("beasty-looking things"): {_Homo_>_Rana_, _Chelone_, _Vipera_,
_Crocodylus_, _Passer_}. Would currently include mammals, other therapsids,
"pelycosaurs".


Chelonopsida ("turtlish-looking things"): {_Chelone_>_Rana_, _Homo_, etc.}.
Would include turtles and whatever the heck they're most closely related to.


Herpetopsida ("snaky-looking things"): {_Vipera_>_Rana_, _Homo_, etc.}.
Would include snakes, other lizards, tuataras, etc.

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).


Ornithopsida ("birdy-looking things"): {_Passer_>_Rana_, _Homo_, etc.}.
Would include birds and other dinosaurs, "lagosuchians", and perhaps
pterosaurs.

Other "classes" could (but need not necessarily) be named analogically for
groups that do not fit into any of the above clades.

--Nick P.
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