A large predatory lizard (Platynota, Squamata) from the Late Cretaceous of South China

Abstract

The Late Cretaceous deposits of the Nanxiong Formation, southern China, have yielded some dinosaur bones and many eggs, but there has been little record of the associated fauna. A new locality in Jiangxi Province has recently produced a fossil lizard assemblage including two genera of herbivores and the partial skull and lower jaws of a terrestrial predator. The latter combines large size, the possession of a small number of recurved, well-separated marginal teeth, a blunt rostrum, and rounded cranial osteoderms. It resembles Estesia from the Late Cretaceous of Mongolia, but is distinct in its jaw morphology and the possession of cranial osteoderms. It is therefore placed in a new genus and species, Chianghsia nankangensis. Phylogenetic analysis groups Chianghsia unequivocally with the Platynota, the group to which living monitor lizards and extinct mosasaurs belong. Within Platynota, there is support for the attribution of Chianghsia to Monstersauria, the group that includes the living venomous Gila monster, Heloderma suspectum, and its fossil relatives. This is the first record of a large terrestrial predatory platynotan lizard from the Mesozoic of southern China.