Early Cretaceous lizards from the Okurodani Formation of Japan

The Early Cretaceous Okurodani Formation of Gifu Prefecture, Central Honshu, Japan, is yielding an assemblage of small freshwater and terrestrial vertebrates which represent some of the oldest specimens of their kind from Japan. Although rare, at least two types of lizards - probably more - have been recovered. The most common form, described here under the name Sakurasaurus shokawensis nov, gen. et sp., is a robust scincomorph with distinctive sculptured frontals and a heterodont dentition in which the anterior teeth are tapering and recurved while the posterior teeth are blunt and striated. Parsimony analysis places it provisionally as a basal scincomorph. Other taxa are represented by isolated elements, including dentaries, maxillae, and some heavily sculptured skull roofing bones which may be anguimorph. This Japanese lizard assemblage differs from roughly contemporaneous assemblages in other Darts of the world and thus contributes to our knowledge of Early Cretaceous lizard diversity in general, and to our understanding of the evolution of Asian lizard assemblages.