In the county of Devon, paleontologists have identified a new species of ancient reptile, Agriodontosaurus helsbypetrae. This discovery is not only older than all previously known members of the Rhynchocephalia group but has also forced scientists to revise their understanding of the evolution of lizards, snakes, and tuataras.
On the coast of Sidmouth in Devon, UK, paleontologists discovered the remains of the ancient reptile Agriodontosaurus helsbypetrae, which lived over 240 million years ago. The find helps to revise ideas about the evolution of lepidosaurs—the group that includes modern lizards, snakes, and the sole living representative of the ancient Rhynchocephalia branch, the New Zealand tuatara.
Although the fossil was collected back in the 1950s, researchers at the University of Bristol only recently applied modern methods, including synchrotron computed tomography. This allowed them to create a 3D model of the skull and study its smallest structural details.
Agriodontosaurus helsbypetrae had large, triangular teeth adapted for hunting insects, as well as several unique features: an open temporal bar, the absence of palatal teeth, and a specific jaw structure. These characteristics suggest that the species emerged several million years earlier than other known Rhynchocephalia members and played an important role in the evolution of ancient reptiles.
Scientists believe that the discovery changes the understanding of the early development of the group that later gave rise to modern snakes and lizards, and confirms the tuatara’s special place as a “living fossil.”