Overview

• University of Bristol researchers name the tiny species Agriodontosaurus helsbypetrae in a study published in Nature on September 10, 2025.
• The fossil lacks palatal teeth and a skull hinge yet retains an open lower temporal bar, contradicting expectations for the earliest lepidosaurs.
• Large, triangular teeth indicate a specialization for piercing and shearing hard-bodied insects, with feeding compared to the modern tuatara.
• High-resolution synchrotron CT at the ESRF in France and the Diamond Light Source in the UK resolved fine details of the 1.5 cm skull without damaging the specimen.
• The specimen, found in 2015 in the Helsby Sandstone Formation in Devon, pushes the confirmed lepidosaur record to the Middle Triassic and points to greater early ecological diversity.