[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re:



Quoting Michael Schmidt <dmschmidt@sprint.ca>:

> there is a 100% (as far as I know) diagnostic trait inherent in
> Daspletosaur teeth and not seen in other tyrranasaur teeth....
> 
> if you look at the face of the tooth, right along the edge next
> to the serration, there is a "wrinkle" that extends out ever so
> slightly.
> 
Which face are you referring to here?  labial?  lingual?  mesial?  
distal?  These "wrinkles," do they look to you like cf. 
_Carcharodontosaurus_ "enamel wrinkles?"  I have seen enamel wrinkles 
very similar to "carch wrinkles" on all sorts of tyrannosaurid teeth 
(probably more than 150 teeth with this feature that I can think of, so 
it doesn't show up on all of them, though that is in no small part a 
preservational issue).  They are VERY obvious in _T. rex_ teeth, in 
particular the premaxillary and distal dentary crowns.  They are very 
similar to "carch wrinkles" in that they start at the carinae (generally 
both--no obvious association with denticles), and cut basally for maybe 
1.5-3mm, then they "flatten out" and head "out" from the carinae across 
the labial and lingual faces of the crowns.  They are less distinct 
proximal to the carinae than are "carch wrinkles" but are more obvious 
in the middle of the labial and lingual crown faces. They occur in 
_Albertosaurus_ and Daspletosaurus_ quite often, as well as in a number 
of non-tyrannosaurid taxa (e.g., I saw them weakly expressed on the 
dentary crowns of the _Liliensternus_ skull in Berlin two years ago).  
Very interesting.  Dunno what it means yet...

-j

----
Josh Smith
Department of Earth and Environmental Science
University of Pennsylvania
240 South 33rd Street
Philadelphia, PA 19104-6316
smithjb@sas.upenn.edu
Project Director, Bahariya Dinosaur Project (http://www.egyptdinos.org)

NOTE: Currently in residence at:
Department of Anthropology
Harvard University
Please address all correspondence and mailings to:
18 Traymore Street
Cambridge, MA 02140
NEW OFFICE PHONE 617.495.1966