Data from: Biomechanical properties of the jaws of two species of Clevosaurus and a reanalysis of rhynchocephalian dentary morphospace

Rhynchocephalians were a successful, globally distributed group of diapsid
reptiles that thrived in the Mesozoic. Multiple species of Clevosaurus
existed worldwide in the Upper Triassic and Lower Jurassic, and they are
characterised by shearing bladelike teeth perhaps functionally analogous
to the carnassial teeth of mammals. Morphometric analysis shows that the
dentary morphospace of clevosaurs differs significantly from that of other
rhynchocephalians. Five Clevosaurus species occupied islands in the
Bristol Channel archipelago of the UK, but generally not those occupied by
mammaliaforms, suggesting dietary character displacement. Identifying the
diet of such ancient, small tetrapods has been difficult. To identify the
nature of their feeding, we apply finite element analysis to two near
complete three-dimensional skulls of the species Clevosaurus hudsoni and
Clevosaurus cambrica to estimate bite force, resistance to bending and
torsion, and the distribution of stresses during biting. Both species had
bite forces and tooth pressures sufficient to break apart chitin,
indicating that like early Mesozoic mammaliaforms, clevosaurs could feed
on tough-shelled beetles and possibly small vertebrates. In addition, the
mechanical advantage of the jaws falls within the range of early
mammaliaforms, so though we cannot demonstrate niche partitioning between
members of both clades, it raises the prospect that they may have been
functionally similar.