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Re: Saltopus... a silesaurid?



2011/5/18 Tim Williams <tijawi@gmail.com>:
>
> However... Nesbitt's recent analysis (2011) showed that the
> "crocodile-normal / crurotarsan" condition is actually primitive for
> archosaurs, with his analysis placing phytosaurs outside the
> Archosauria (sensu stricto).  In his words, the classic 'crocodile
> normal ankle' is rendered plesiomorphic for Phytosauria + Archosauria
> (= Crurotarsi).  So all archosaurs would be crurotarsans, including
> those on both the crocodile- and bird-lines.
>
According to a Figure in Sereno 1991 (Memoir of the SVP) on the tarsus
of a phytosaur, it was apparent that the "astragalar peg" was scarcely
developed, the astragalo-calcaneal articulation being not much
different from the common basal archosauriform condition. So,
considering phytosaurs as crocodile-normal is partially a "courtesy"
with them (as would have say Romer).