RE: Evolution of tyrannosauroid bite power

["Thomas R. Holtz, Jr." <tholtz@umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu] 
> On Behalf Of Jamie Stearns
> Sent: Wednesday, December 19, 2007 9:32 AM
> To: dinosaur@usc.edu
> Subject: Re: Evolution of tyrannosauroid bite power
> 
> I'm not sure about when the strong bite power evolved,but I 
> do seem to recall that Dilong and other early tyrannosaurs 
> were mainly identified as such from their cranial anatomy, 
> which would suggest that a distinctive skull was one of the 
> first things to evolve, and this may have some bearing on 
> when the jaw structure developed. However, I've yet to really 
> look at the structure of Dilong's jaws or anything for 
> evidence of its biting power. 
> 

The strong tyrannosaur bite did seem to evolve early on, although in
stepwise fashion.

Snively et al. (2006) discuss this to some degree in:
Snively, E., D.M. Henderson & D.S. Phillips. 2006. Fused and vaulted nasals
of tyrannosauroid dinosaurs: implications for cranial strength and feeding
mechanics. Acta Palaeontologica Polonica 51:435-454.
(Available for free online at http://app.pan.pl/acta51/app51-435.pdf)

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Earth, Life & Time Program, College Park Scholars
http://www.geol.umd.edu/~jmerck/eltsite/
Fax: 301-405-0796

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA