Ancient Tooth Reveals Reptilian Predator Attack Millions of Years Ago

About 210 million years ago, the supercontinent of Pangea was just starting to break up. At the time, dog-sized dinosaurs hid from the predators at the top of the food chain: reptilian predators called phytosaurs and rauisuchids. Now, scientists have found that these predators may have interacted with each other far more often than previously thought.

Researchers once believed that the two top predators didn't interact much with at all since one kept to the water while the other was land-based. Yet new fossil evidence is now changing that particular outlook.

"Phytosaurs were thought to be dominant aquatic predators because of their large size and similarity to modern crocodylians, but we were able to provide the first direct evidence they targeted both aquatic and large terrestrial prey," said Michelle Stocker, one of the researchers, in a news release.

In this case, they found the tooth of a phytosaur lodged in the thigh bone of a rauisuchid that was 25 long and four feet high at the hip when alive. This tooth presents evidence that these creatures interacted with each other along the food web.

"It was remarkable we were able to reconstruct a part of an ancient food web from over 210 million years ago from a few shallow marks and a tooth in a bone," said Sterling Nesbitt, one of the researchers. "It goes to show how careful observation can lead to important discoveries even when you're not seeking those answers."

The findings reveal a little bit more about these ancient animals and how they interacted with one another. By looking at fossil evidence, researchers were able to learn a bit more about some of the first, large reptiles to roam our planet.

"This research will call for us to go back and look at some of the assumptions we've had in regard to the Late Triassic ecosystems," said Stocker. "The distinctions between aquatic and terrestrial distinctions were over-simplified and I think we've made a case that the two spheres were intimately connected."

The findings are published in the journal Naturwissenchaften.