T. rex hunted live prey

Fossils yield tooth in healed wound of another dinosaur

In a healed wound in the tailbone fossil of a duck-billed dinosaur (left, site of wound in red), researchers found a Tyrannosaurus rex tooth crown lodged in a pair of fused bones (right, circle denotes location of the tooth). This discovery is direct evidence that T. rex hunted.

R.A. DePalma II et al/PNAS 2013

By Erin Wayman

July 15, 2013 at 2:43 pm

Tyrannosaurus rex’s fearsome reputation is intact. New fossils confirm that the dinosaur did indeed hunt down prey. In recent years, some paleontologists have argued that T. rex was actually a scavenger, not a predator.

Unearthed in the Hell Creek Formation in South Dakota, two tail vertebrae from a duck-billed dinosaur that lived roughly 70 million years ago contain evidence of a bite. Embedded in the fused bones is the crown of a tooth that matches the size and shape of T. rex teeth. Bone growth over the tooth indicates that the bite had healed and that the animal had survived at least a few months or years after the attack.

That’s evidence that T. rex nipped the dinosaur while it was alive, Robert DePalma of the Palm Beach Museum of Natural History in Fort Lauderdale, Fla., and colleagues report July 15 in the Proceedings of the National Academy of Sciences.

Although the discovery is clear evidence that T. rex hunted, it doesn’t rule out the possibility that the dino also scavenged some of the time, the team says.