The full text of the report, titled “Ancestors of ‘vegetarian’ Dinosaurs actually liked Meat,” was published on Live Science on Tuesday.
It has long been thought that Tyrannosaurus Rex was a carnivore, while the pliosaurs quietly nibbled on leaves. However, the results of a new study suggest that dinosaurs had a far more diverse diet than previously thought.
To get a better idea of what different dinosaurs actually ate, paleontologists at the University of Bristol in the UK scanned the skulls of several dinosaurs — including the smaller alveodon and the long-necked Diplodocus, both of which are thought to be herbivorous — and created 3D models of their teeth.
Lead author Antonio Mayoral, a senior research fellow at the University of Bristol’s School of Earth Sciences, said: “Teeth can provide clear clues about what animals eat because they are the tools they use to break down food. Different tooth shapes can effectively handle different types of food.”
He added: “In dinosaurs, we see teeth in an amazing variety of shapes, from knife-like, conical, triangular, leaf shapes. This suggests that dinosaurs developed different feeding habits and a wide range of diets. What’s interesting is that many of these tooth shapes are present in the very earliest dinosaurs, suggesting that they may have always had a very diverse diet.”
In fact, the ancestors of plant-eating dinosaurs didn’t make themselves strictly “vegetarians.” Instead, they were likely to gorge on meat and insects, just as carnivorous dinosaurs would have preyed on them.
“This study is the first modern statistical demonstration that early dinosaurs explored different types of food and were ecologically diverse,” Mayoral said.
“Our results suggest that two of the three plant-eating dinosaur lineages were not originally herbivores,” he said. Sauropods, early relatives of Diplodocus and other large long-necked dinosaurs, transitioned from carnivores to herbivores during the Triassic. And the early ornithischian dinosaurs that formed the later Triceratops and Hadrosaurs probably preferred an omnivorous diet.”
The findings were published December 16 in the journal Science Advances.