Bone-gnawing carnivorous dinosaur replaced teeth rapidly

Scientists have been researching a species of meat-eating dinosaur that lived in the Madagascar region about 70 million years ago. The dino is called the Majungasaurus, and what the team of researchers has found is that the creature replaced its teeth roughly two to 13 times faster than other carnivorous dinosaurs.

Majungasaurus was forming a new tooth in each socket every couple of months. The scientists say that the rapid replacement of teeth means that the dinosaur was wearing its teeth down quickly. They believe that the creature may have been gnawing on bones.

Evidence of the gnawing action has been found in the form of scratches and gouges that match the spacing and size of their teeth on a variety of bones from animals that would have been Majungasaurus' prey. Replacing teeth quickly isn't unheard of in modern animals, and some animals today still gnaw on bones, rodents being a bone-munching example.

The fast tooth replacement puts Majungasaurus in the same league as sharks and big herbivorous dinosaurs. The recent study into Majungasaurus also looks at two additional species of predatory dinosaur, including the Allosaurus and Ceratosaurus. The team used a collection of isolated fossil teeth to examine the microscopic growth lines in them.

The team found that rather than being deposited once a year, these growth rings said to be similar to tree growth rings, were deposited daily. The team also used CT scans on intact jaws to visualize unerupted teeth growing inside the bones to estimate tooth replacement rates. The team says that future research will be able to use their study to estimate the tooth-replacement rate in dinosaurs without destructively sampling the teeth. The scientists hope their project spurs more research into other species.