by It has long been believed that tyrannosaurus rex I was a carnivorous maniac while long-necked dinosaurs it calmly chewed the leaves in the background. However, a new study suggests that dinosaur diets were much more diversified than previously thought.
To get a better idea of what different dinosaurs actually ate, paleobiologists at the University of Bristol in England examined CT scans (computed tomography) from the skulls of several genera of dinosaurs, including small bipeds thecodontosaurus and long neck diplodocusboth considered herbivores, and created 3D models of their teeth.
“Teeth can give good clues about what an animal eats because they are our tools for breaking down food.” Antonio Ballell Mayoral. (opens in a new tab), the study’s lead author and a senior research associate in the University of Bristol’s School of Earth Sciences, told Live Science in an email. “As such, different tooth shapes are expected to be efficient at processing different types of food.
“In dinosaurs, we see an impressive diversity of tooth types, including blade-shaped, conical, triangular, leaf-shaped teeth, etc.”, he added. “This is an indication that dinosaurs evolved different eating habits and specialized in a wide range of diets. Interestingly, many of these different types of tooth shapes were already present in the earliest dinosaurs, suggesting that they could have been highly diverse.”
The researchers then compared the shape and function (bite force) of the dinosaur teeth with those of living reptiles, such as different species of lizardincluding monitor lizards and skinks, as well as geckos, snakes, and crocodiles.
Related: The entrails of a voracious carnivorous dinosaur are preserved in an exceptionally rare fossil
“Our knowledge of the relationship between tooth shape and diet is based on information from living species,” Ballell Mayoral said. “For example, sharp, curved teeth are better for piercing and cutting soft foods like meat, and are typical of carnivores. On the other hand, straight teeth with denticles [serrations] they are more efficient at breaking down tougher elements such as some plants and insect exoskeletons, and are present in herbivores and insectivores.”
As an example, Ballell Mayoral pointed to the feeding habits of some of the earliest known dinosaurs, including bipedal theropods, armored ornithischians, and long-necked sauropodomorphs.
“Some of the earliest dinosaurs [such as theropods] that were classified as carnivorous in our study have teeth similar to those of monitor lizards, being pointed, curved and finely toothed,” he said. “In contrast, iguanas have lance-shaped teeth with thick denticles resembling those of the first dinosaurs classified as herbivores [like the ornithischians and sauropodomorphs.]”
Indeed, the ancestors of herbivorous dinosaurs weren’t limited to the salad bar. Rather, they were probably eating meat and insects, just like the predators that were attacking them.
The researchers found that many early dinosaurs adopted “different dietary habits” that were a “very important factor that allows groups of organisms to diversify,” he said.
“This study is the first to show with modern statistical methods that early dinosaurs explored different types of diets and were ecologically diverse,” he said. “Our research supports that two of the three main lineages of dinosaurs, which adapted to a plant diet, did not start out as herbivores. Sauropodomorphs, early relatives of diplodocus and other long-necked giants, switched from being carnivorous to herbivorous during the Triassic period. And the first ornithischians, which gave rise to vegetable dinosaurs such as triceratops and much later duck-billed dinosaurs might have preferred an omnivorous diet.”
And yes, t rex he really was a meat lover.
The findings were published December 16 in the journal Progress of science (opens in a new tab).
