University of Bristol, 16 December 2022.

Professor Emily Rayfield, senior co-author:

>“Our analyses reveal that ornithischians – the group that includes many plant-eating species like the horned dinosaurs, the armoured ankylosaurs and the duck-billed dinosaurs – started off as omnivores.

>“And another interesting finding is that the earliest sauropodomorphs, ancestors of the veggie long-necked sauropods like Diplodocus, were carnivores. This shows that herbivory was not ancestral for any of these two lineages, countering traditional hypotheses, and that the diets of early dinosaurs were quite diverse.”

Lead author Dr. Antonio Ballell:

>“We investigated [dinosaur diet] by applying a set of computational methods to quantify the shape and function of the teeth of early dinosaurs and compare them to living reptiles that have different diets. This included mathematically modelling their tooth shapes and simulating their mechanical responses to biting forces with engineering software.”

Professor Mike Benton, co-author:

>“With this battery of methods, we were able to numerically quantify how similar early dinosaurs were to modern animals, providing solid evidence for our inferences of diets. Theropod dinosaurs have pointy, curved and blade-like teeth with tiny serrations, which behaved like those of modern monitor lizards. In contrast, the denticulated teeth of ornithischians and sauropodomorphs are more similar to modern omnivores and herbivores, like iguanas.”

Science Advances, 2022. DOI 10.1126/sciadv.abq5201