How chewing like a cow helped early mammals thrive
(PHYSorg.com Archaeology & Fossils)

You probably haven`t given much thought to how you chew, but the jaw structure and mechanics of almost all modern mammals may have something to do with why we`re here today. In a new paper published this week in Scientific Reports, David Grossnickle, a graduate student in the Committee on Evolutionary Biology at the University of Chicago, proposes that mammal teeth, jaw bones and muscles evolved to produce side-to-side motions of the jaw, or yaw, that allowed our earliest ancestors to grind food with their molars and eat a more diversified diet. These changes may have been a contributing factor to their survival of the mass extinction at the end of the Cretaceous Period 66 million years ago.