Diphydontosaurus

Diphydontosaurus was a sphenodontian reptile from the Late Triassic of England and Italy. This small animal was related to the living tuatara (Sphenodon). Diphydontosaurus may have hunted and eaten insects in the crevices of ancient caves using its claws. It may have grown to a length of 4 inches (10 cm). It is a rhynchocephalian more derived than Gephyrosaurus, yet more primitive than Planocephalosaurus, and shares traits with both of them.

Description
Diphydontosaurus was a small sphenodontian, measuring up to 10 cm (4 in) long. It had long, sharp claws to help it catch its prey,[1] and peg-like piercing teeth to help it eat insects. These features are shared with the other primitive rhynchocephalians Gephyrosaurus and Planocephalosaurus.

Classification
Diphydontosaurus is known from many mostly complete specimens,[1] which means that its classification as a rhynchocephalian is quite certain. In an analysis by Oliver Rahut and colleagues in 2012, it was found that Diphydontosaurus is the second most basal rhynchocephalian, after Gephyrosaurus, and the most primitive sphenodontian, more primitive than Planocephalosaurus. Their analysis is shown below: