Analysis of the teeth of three major types of carnivorous dinosaurs reveal similar wear patterns regardless of the size of the dinosaur and of the tooth itself. As it turns out, the dinosaurs employed the same feeding methods but varied in prey selection based on their teeth strength and shape.
Upon analysis of the teeth of predatory theropods from the Upper Cretaceous, researchers found that the creatures employed a feeding method called the puncture and pull, wherein they used their serrated teeth to puncture the skin of their prey and then pull their heads back while still biting down.
This was gathered based on the patterns of small scratches on the teeth, specifically the parallel scratches that appear when the dinosaurs bite down and the oblique scratches that form when the head is pulled back. These scratches were observed in all the tooth samples analyzed, except for one sample that has slightly eroded.
"We found the microwear patterns were similar in all of the teeth we examined, regardless of the size of the dinosaur, the size of the tooth or the shape of the denticles," said Ryan Wilkinson of the University of Alberta Department of Biological Sciences, coauthor of the study.
Different Prey Choice
Although the theropods were found to have employed a similar hunting method, researchers also found that they most likely had different prey choices mainly because of certain differences in their teeth. Because their teeth still varied in shape and strength, making some stronger and others more prone to breakage, the dinosaurs were practically forced to favor certain types of prey over others.
For instance, while the Dromaeosaurus and Saurornitholestes were likely adapted to handle struggling prey and processing bone, Troodontids likely preferred softer, smaller, and possibly even immobile prey, as their teeth were likelier to fail at non-optimal bite positions and angles.
"All these dinosaurs were living at the same time and place, so it is important to know if they were competing for food resources or if they were aiming for different prey," said the study's first author, Angelica Torices of Universidad de La Rioja, Spain.
The study is published in the journal Current Biology.