Dietary Damage to Teeth Led to Starvation of Triassic Herbivores, Indicate Findings

New research has revealed that a species of rhynchosaurs, sheep-sized reptiles that lived between 250 and 225 million years ago, eventually starved to death due to their diet causing severe wear and tear on their teeth. These herbivores roamed the earth during the Triassic Period, which was characterised by warm climates and tough plants that proved to be challenging even for the rhynchosaurs’ specialised teeth. Using scans of fossils found in Devon, the study found evidence that suggest that as they aged, these early herbivores’ jaws simply wore out, leaving them unable to eat enough and eventually starving to death.

Professor Mike Benton, the team leader of the study, was amazed by how dominant these rhynchosaurs were in their ecosystems, comparable to sheep and antelopes. However, their specialised dental systems adapted to deal with tough plant food resulted in wear and tear that eventually led to their demise. Comparing jaw bone specimens of rhynchosaurs, the researchers found that as these animals grew, the area of the jaw that was under wear moved backwards, bringing new teeth and bone in wear. However, their growth slowed down at a certain age, and the wear area got deeper, leading to their eventual starvation. In the end, climate change and the availability of plants led to their extinction as dinosaurs took over.

With their unique teeth, rhynchosaurs were able to diversify twice in the Middle and then in the Late Triassic. They played an essential role in the ecosystems on land during the Triassic, after the world’s greatest mass extinction at the end of the preceding Permian Period. However, as the study shows, their specialised diet ultimately caused their downfall. The research is published in the Palaeontology journal.