Study On rex Biting

["Richard W. Travsky" <rtravsky@uwyo.edu>]

http://dsc.discovery.com/news/briefs/20040614/trex.html

June 15, 2004  Tyrannosaurus rex's head served as a giant shock absorber
to withstand the dinosaur's bone-crushing, flesh-tearing eating habits,
according to a new study that suggests the dino might have had the world's
most deadly bite.

The study, published in the current Royal Society's Proceedings B
(biological sciences), supports a 1996 paper that found T.rex fed using a
puncture-pull method, meaning that the 40-foot-long, 12-foot-tall
carnivore first bit down on its prey to crunch bone, and then pulled back
to rip through flesh. 

For the new analysis, paleontologist Emily Rayfield from the University
of Cambridge created digital models of the deadly dino's 4 1/2-foot skull
and then used a computer program to study how stress during eating would
affect each section of the skull.

She particularly looked at sutures, or places where two bones meet. In
some animals, sutures can be fused, but for T.rex, Rayfield found that
these areas were mobile to dissipate stress and strain, and to allow for
flexing.

According to the study, the real secrets to the seven-ton creature's
feeding success appeared to be its huge, bumpy boned snout, its lower
cheeks, and its specially designed teeth.

Rayfield explained to Discovery News that paired, thickened nasal bones in
the dino's snout helped to resist compression and shearing. Sutures in the
lower cheeks allowed for sliding and flexing. They also helped to absorb
shock. Finally, T.rex's six-inch, razor-sharp teeth had a peg-like design
perfect for chomping up meat, such as other dinosaurs.
...
T.rex's puncture-pull bite and is an assistant professor of anatomy and
dinosaur paleobiology in the Department of Biological Science at Florida
State University, told Discovery News that Rayfield presents "exquisite
work" and "her conclusions are likely spot on."

Erickson said, "I don't think the findings so much confirm the
puncture-and-pull theory since it is based on actual trace evidence (bite
marks), but rather they provide a logical explanation for how the skulls
of these animals were mechanically well-suited for such activity."

He added that T.rex had such a powerful bite that when the monstrous
animal bit into bone and flesh, it was like drawing "a hot knife through
butter."