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Re: Removing segnosaurs from Theropoda
In a message dated 95-08-29 20:50:22 EDT, email@example.com (Jason Head)
> Yes, and if crocodylian mandibles were found in Triassic deposits,
>they'd be called phytosaurs. The downturned Maxillae are very similar, but
>the story is just not that simple.
Right. But it does help my case.
> Until we learn more about segnosaurs, a generally accepted answer will have
to wait >(esp. the relationships between segnosaurs and therizinosaurs: I am
not convinced by
>Russell's descriptions and analyses).
When you get right down to it, Russell's _Alxasaurus_ is the genus that
places _Therizinosaurus_ into Segnosauria, because it has both a tetradactyl
pes like that of _Segnosaurus_ and a tridacyl manus with large claws like
that of _Therizinosaurus_. There is a tetradactyl pes that Perle referred to
_Therizinosaurus_ provisionally, but we didn't really know he was right until
_Alxasaurus_ was described.
>As for "Thecodontians", you don't have to be a cladist (and/or strictly
adhere to >monophyletic groupings), to recognize that "thecodont" has NEVER
described an >actual group of related taxa. It was a garbage can ( a la
megalosaur), for poorly
>understood archosaurs, and has since been abandoned.
Except by me, an old stick-in-the-mud.