A Long‐bodied Lizard From the Lower Cretaceous of Japan

Platynotan lizards underwent a dramatic Late Cretaceous radiation into marine habitats. Beginning with small‐bodied forms, the lineage culminated with the mosasaurs, large predatory lizards with a world‐wide distribution in the Santonian–Campanian. Moreover, the marine squamate radiations of the Cenomanian–Turonian are remarkable in having produced a range of long‐bodied, reduced‐limbed swimmers (dolichosaurs, adriosaurs, coniasaurs and limbed snakes) that seem to have thrived in the shallow coastal environments of the Western Tethys region. Until now, none of these long‐bodied aquatic squamates has been recorded prior to the Cenomanian, none has been recovered from a non‐marine locality and none is known from Asia. Here we describe a small, gracile, long‐bodied mosasauroid lizard from a swampy continental deposit in the Lower Cretaceous of Japan.