Protopyknosia

Protopyknosia is an extinct clade of archosauriform reptiles from the Late Triassic of India and the United States. First identified by Sterling Nesbitt et al. in 2021, the clade contains two genera: Kranosaura and Triopticus. Members of Protopyknosia characteristically have an unusually domed head reminiscent of the later pachycephalosaurian dinosaurs in an example of convergent evolution.