RE: Spinosaur crests & sails

["Marco Mendez" <spinosauroidea@onebox.com>]

I wrote: 
> >>About the crest, the crest is not so big on all spinosaurs, a long,
low crest (or part of it) can be seen in Taquet et Russell (1998) in
their description of _Cristatusaurus lapparenti_, I know this might be
a
 syno0nym to _S. tenerensis_, but that is another argument. Anyway, an
articulated premaxilla and maxilla are referred to _S. maroccanus_, 
a possible junior synonym to _Spinosaurus aegyptacus_, but indeed a 
spinosaurine.<<

Tracy Ford wrote:   
>> I disagree. I've done some research on this and IMHO _S. aegyptacus_
 had a much shorter and taller skull than _S. maroccanus_.<<<

Sereno et al. (1998) suggests that all spinosaur material from North
Africa from albian- Cenomian- age rocks is to be reffered to S. aegytpciaus.
I have seen both the illustrations of the dentary of 
_S. aegypticus_ and _S. maroccanus_. S. maroccanus has a long, low narrow
premaxilla + maxilla. S. aegytiacus seems to be long and narrow. 
I am not very sure of the sizes of both, I know they're big. It may be
possible they are the same species but both specimens are at different
stages of growth. (I have discussed this before, and my conclusion was:
we'll find out when a rather complete S aegytpcus is found, or a lower
jaw with the upper jaws of S. maroccanus. 
Sereno et al. say that the proportions and adddtional material are questionable.
Thus, they refer to _S. maroccanus_ as a nomen dubium. 
   
-marco  
-- 
Marco  Mendez
Atomic DinoLab, University of Chicago 
spinosauroidea@onebox.com - email
(773) 377-5006 x2159 - voicemail/fax
AIM: Spinosauroidea

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