RE: Ornitholestes

["Jordan Mallon" <j_mallon@hotmail.com>]

> From: "Williams, Tim" <TiJaWi@agron.iastate.edu>

> Says O. Rauhut: "Paul (1988a, b) argued for a close relationship >between 
> _Ornitholestes_ and _Proceratosaurus_, and reconstructed the >skull of the 
> former taxon with a nasal horn.  My observations of the >type specimen of 
> _Ornitholestes_ (AMNH 619) revealed little evidence >for the presence of 
> such a structure; the apparent upward flexure of >the posterior border of 
> the external nares on the left side of the >skull is caused by a break and 
> subsequent ventral displacement of the >ascending process of the maxilla 
> and the nasals."
>
> Pity.  A horn for _Ornitholestes_ would have been so much cooler.

What, then, does he say about _Proceratosaurus_, who is also believed to 
have had some type of nasal horn?  If the two were so closely related (and 
it would certainly seem so by looking at the rest of the skull), why would 
one have a horn (or crest) and not the other?  (Seems like the answer might 
be obvious, but I have a hard time accepting the idea that two apparently 
closely-related forms would have differed so significantly in such a 
feature.  _Dilophosaurus wetherilli_ and _D. breedorum_ aside.)

-Jordan Mallon

http://www.geocities.com/paleoportfolio/

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