An early herbivorous lizard from the Lower Cretaceous of Japan

Abstract

The Lower Cretaceous Tetori Group of Japan has yielded diverse freshwater and terrestrial vertebrate assemblages. The most productive small vertebrate locality is the 'Kaseki-Kabe' or 'fossil-bluff' at Kuwajima, Hakusan City, Ishikawa Prefecture. These deposits have produced at least six distinct lizard taxa of which one, described and named here as Kuwajimalla kagaensis, has lanceolate denticulate teeth convergent on those of the living Iguana. This type of dentition is rare among living lizards and is usually considered indicative of herbivory and, more specifically, folivory. Kuwajimalla kagaensis provides the earliest unambiguous record of squamate herbivory. Comparisons with modern and fossil lizards suggest that Kuwajimalla may be an early relative of the macrocephalosaurines, a group of large herbivores well represented in the Upper Cretaceous of Mongolia. © The Palaeontological Association, 2008.