The respective top predators of the land and ocean environments of 210 million year ago — phytosaurs and rauisuchids — apparently hunt and fought with each other, according to new research from the University of Tennessee and Virginia Tech’s Department of Geosciences.
The new finding is the result of researchers recently finding the tooth of a phytosaur embedded in the thigh bone of a rauisuchid. The tooth apparently broke off and was left buried about two inches deep in the bone, before the bone then healed over (the rauisuchid obviously survived). For some perspective, rauisuchids grew to be at least 25 feet long and 4 feet high at the hip.
“Phytosaurs were thought to be dominant aquatic predators because of their large size and similarity to modern crocodylians,” stated researcher Michelle Stocker, “but we were able to provide the first direct evidence they targeted both aquatic and large terrestrial prey.”
“Finding teeth embedded directly in fossil bone is very, very rare,” researcher Stephanie Drumheller noted. “This is the first time it’s been identified among phytosaurs, and it gives us a smoking gun for interpreting this set of bite marks.”
“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,” stated fellow researcher Sterling Nesbitt. “It goes to show how careful observation can lead to important discoveries even when you’re not seeking those answers.
“We came across this bone and realized pretty quickly we had something special,” Nesbitt said. “There are many bones that get dug up, not all are immediately processed, prepared, and studied. No one had recognized the importance of this specimen before but we were able to borrow it and make our study.”
The researchers used CT scans and a 3-D printer to reconstruct the embedded tooth. There are a number of other bite patterns on the bones as well — indicating that the animal was targeted at least twice by phytosaurs over the course of its life.
“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,” Stocker stated. “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.”