The New York Times’ Trilobites column has a story about Tyrannosaurus rex.  Just how did T-rex get its nasty bite… slowly over the years. In paper published in the journal The Anatomical Record, scientists looked at how the powerful oral feature had evolved.

It was not easy for the researchers to build 3-D skull models of nine tyrannosaur species for their analysis. Evan Johnson-Ransom, a doctoral student at the University of Chicago who led the research, said that just reconstructing digital skulls of two Asian species “took approximately three months since we had to work with flattened specimens.”

But the team endured, ultimately finding that tyrannosaur snouts fit two basic shapes: gracile for those that were more slender, such as earlier forms of tyrannosaur and juvenile T. rex, and then robust for the heftier snouts, like that of an adult T. rex. Each 3-D model was then subjected to finite element analysis, a technique that determines the stress and strain on biological structures. Stress, in this context, refers to the amount of force exerted upon the skull bones, which were capable of handling extreme exertions.