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Re: Defending grades (Was: Re: Archaeopteryx (rant))



Jean-Michel wrote-

> Shouldn't it be :
> -Early tetrapods (all forms)
> +-Amphibia (Lissamphibia)
> |
> +-Amniota
> `--+--Synapsida
>   |  `--+==pelycosaurs
>   |     `--Mammalia
>   `--Reptilia
>      `--+?-Testudines
>         `--+--+--Squamata
>            |  `--Sphenodon
>            `--+--Crocodilia
>               `--Aves

Seems identical to mine, except that I left stem stegocephalians out, didn't
note Amphibia contains crown amphibians (Lissamphibia), or name the
synapsid+sauropsid node (Amniota).  I did say mine was simplified.  Note the
definition of Tetrapoda is a crown group (Laurin and Reisz, 1997), so "early
tetrapods" in your tree are really stem stegocephalians.

Mickey Mortimer