BOB HIRSHON (host):
The tooth revealed. I’m Bob Hirshon and this is Science Update.
Paleontologists have identified oldest known bite marks from a mammal, on dinosaur bones and others dating back 75 million years. Michael J. Ryan, curator of vertebrate paleontology at the Cleveland Museum of Natural History, says the biter had paired, opposing teeth, seen only in mammals at the time. Most likely, it belonged to a group of rodent-like mammals called multituberculates.
MICHAEL RYAN (Cleveland Museum of Natural History):
If you saw one living today, it would be reconstructed something like a rat, or maybe a squirrel with a big bushy tail. And we suspect, just like modern living rodents, they needed calcium sources, and they would look for defleshed, exposed bone to actually gnaw on to get that calcium source.
He says the find offers a rare glimpse of the smaller, more fragile species that lived in the dinosaurs’ shadows. I’m Bob Hirshon, for AAAS, the science society.