Scientists are confused by the teeth of the Tyrannosaurus Rex.

A series of small holes in the jaw of the largest tyrannosaurus rex on the planet remains a big question for researchers.

Reenactment of Tyrannosaurus Rex Sue hunting. Video: YouTube.

Teeth full of small holes is an unusual feature in the fossil skeleton of the world's largest tyrannosaurus rex named Sue and so far paleontologists have not been able to give a reasonable explanation, according to International Business Times.

Measuring 12.3 metres long and 3.7 metres tall, Sue was a truly terrifying monster when she was alive. Her skull was nearly 1.5 metres long and almost all of her long, sharp teeth were still preserved intact.

The small holes in Sue’s teeth were easy to see. The holes were round and had smooth edges, indicating that the jawbone had healed after the damage. Their presence was not fatal, although the researchers’ two theories about what caused them were not pleasant.

Sue's teeth have many small holes. Photo: Wikimedia.

The first theory is that the holes were formed by a vicious attack by another Tyrannosaurus. The second theory is that the holes were caused by a parasite that Sue contracted while eating her prey. The infection caused painful abscesses that ruptured the bone from the inside out.

But analysis of the fossil skull using 3D scanning showed that neither theory fits. The spacing between the holes is unusual and cannot be explained by a normal bite mark. What makes it even more puzzling is that the holes are not at the right angle to have been left by another dinosaur’s teeth.

The 3D scan also ruled out the parasitic infection hypothesis. If Su had an infection, the holes would have started on the inside of her teeth and spread outward. In reality, the holes gradually thinned out from the outside.

In a report published on July 5 in the journal Plos One, researchers at the Massachusetts Institute of Technology said more in-depth tests are needed to find the exact answer to the origin of the small holes in Sue's teeth.

According to VNE