Dry land and the open ocean have their own apex predators, and ne’er the two shall meet, usually. You wouldn’t expect to find evidence of a battle between a lion and a shark, for instance (though that would be neat). However, researchers at Virginia Tech have discovered a 210 million year old fossil depicting exactly that: The tooth of a phytosaur, the dominant Triassic Period aquatic predator, embedded in the thigh of a rauisuchid, its dry-land counterpart.

“Phytosaurs were thought to be dominant aquatic predators because of their large size and similarity to modern crocodylians,” said Michelle Stocker, a vertebrate paleontologist with the Virginia Tech’s Department of Geosciences “but we were able to provide the first direct evidence they targeted both aquatic and large terrestrial prey.”

The rauisuchid was no slouch – it stood about four feet high at the hip and measured 25 feet long. The phytosaur tooth was found buried two inches within the rauisuchid bone, but was healed over. This particular rauisuchid, it seems, survived the attack. Such a find, the researchers say, is very rare.

Using CT scans and a 3D printer, the researchers were able to reproduce the bone and tooth. Evidence suggests that the embedded tooth was not this rauisuchid’s only brush with phytosaurs, as there were signs of multiple attacks.

The rare find also allows scientists to re-imagine what the Triassic Period food chain may have looked like.

“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, also of Virginia Tech. “It goes to show how careful observation can lead to important discoveries even when you’re not seeking those answers.”

Stocker said that the dichotomy between the terrestrial and aquatic ecosystems may need to be re-thought. Where it was once assumed that the two were wholly separate, it now appears that the two may have crossed over more than anyone previously thought.