Dilophosaurus (was Re: Help indentifying dino species!)

["Timothy Williams" <twilliams_alpha@hotmail.com>]

Actually, it wasn't Mike who wrote this (sorry Mike) but Nick Pharris (sorry 
Nick).

> T. Mike Keesey wrote:
>
> > > > _Dilophosaurus_:
> > > > _D. wetherilli_ (probably the only valid species of _Dilophosaurus_;
> > _"D."
> > > > sinensis_ does not belong in this genus).
> > >
> > > You're forgeting about the newly described D. breedorum.
> sorry Nick).

With respect to the crestless-ness of the type species _D. wetherilli_, 
Welles (1984) thought he saw the bases of two thin bony plates on the skull 
roof of the type specimen (UCMP 37302). Of course, this was after the 
specimen showing the distinctive double-crest (UCMP 77270 = _D. breedorum_) 
had been found, prompting Welles to re-examine the type.

UCMP 77270 is a larger and more robustly-built specimen than the other two, 
and differs in certain skeletal proportions.  Rowe and Gauthier (1990) 
regarded this specimen as a robust morph of _D. wetherilli_, which I think 
has been the approach taken by most authors.

AFAIK, until the publication of Welles' description of UCMP 77270 by Stephen 
Pickering*, the double-crest of _Dilophosaurus_ had never ever been 
described, only figured.

* http://www.cmnh.org/fun/dinosaur-archive/1999Dec/msg00097.html

If I'm wrong about any of this, fire away!


Tim


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