First Record of a Basal Neoceratopsian Dinosaur from the Late Cretaceous of Kazakhstan
The oldest known ceratopsians come from the Late Jurassic of China (Zhao et al. 1999; Xu et al. 2006). During the Early Cretaceous, the basal ceratopsian Psittacosaurus was among the most common dinosaurs in Asia but more derived basal neoceratopsians were quite rare on that continent (Xu et al. 2002; Makovicky and Norell 2006). Basal neoceratopsians became more abundant in the Late Cretaceous of Mongolia and China, although they are not known in this region from the latest Cretaceous (You and Dodson 2004; Alifanov 2008). In contrast, basal neoceratopsians are rare during the Early Cretaceous in North America but became common and diverse during the Campanian and Maastrichtian (You and Dodson 2004; Chinnery and Horner 2007). Little is known about the evolutionary history of this group in more inland regions of what are now Kazakhstan and adjoining countries. Asiaceratops documents the presence of basal neoceratopsians in the Cenomanian of Uzbekistan (Nessov et al. 1989). Here we report on the first record of a basal neoceratopsian in the Late Cretaceous of Kazakhstan, based on two cranial bones from the Turonian Zhirkindek Formation in the northeastern Aral Sea region.