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RE: The Croc That Wanted to Be a Dinosaur




Jaime Headden wrote:

Alternate title, from M. Keesey: "Crocs: The Original Dinosaurs"

The amount of convergence between Triassic archosaurs and later dinosaurs is astonishing. Not just _Shuvosaurus_ as an ornithomimosaur-mimic ("ornithomimomimosaur"), but also tyrannosaur-mimics (_Postosuchus_), ornithischian-mimics (revueltosaurs) and probably ornithurine-mimics (_Protoavis_, or part of it). We can probably throw aetosaurs in the mix as ankylosaur-mimics. Now, if can only figure out what those pachcephalosaur-like domes from the Triassic of India really belong to... (Chatterjee originally touted them as evidence for Triassic pachycephalosaurs.)


As Mike Keesey noted, the forelimbs of_Effigia_ are extremely short. Is _Effigia_ the first incontrovertible evidence for obligate bipedality in the Suchia? I know the sphenosuchians include some gracile taxa that had an erect gait, but they were probably facultative bipeds at best (and I'm not sure if _Hallopus_ was a biped.) Same for ornithosuchids.

It is also notable that many of tese features, as suggested by Nesbitt and
Norell, are found in various Chinle archosaurs, such as the "chatterjeeids".

Nesbitt and Norell also suggest that the Argentine archosaur _Sillosuchus_ might belong to this group.


There is a family Chatterjeeidae Long and Murry, 1995. So even if _Chatterjeea_ is a junior synonym of _Shuvosaurus_, then Chatterjeeidae remains as an available family name.

Note that not only is *Lagerpeton* included is a phylogeny testing the early
placement of various crurotarsans, but so is *Marasuchus* and both are
dinosauromorphans. Technically, so is Pterosauria....

Darn... just as Dave Peters had convinced me that pterosaurs were lizards. :-)


Finally, Nesbitt and Norell note that this data provides evidence that the
cranial elements of *Shuvosaurus* belong to postcranial elements described as
*Chatterjeea*.

I don't want to tread on any corns... but I wonder how _Gojirasaurus_ fits into all of this, given its proposed chimeric nature. Again, I don't have an opinion either way on this.


Cheers

Tim