First Record of Stegosaur (Ornithischia, Dinosauria) from the Aptian–Albian of Mongolia

The first Mongolian stegosaur, Mongolostegus exspectabilis gen. et sp. nov., Stegosauridae (Ornithischia), represented by a series of anterior caudal vertebrae and bones of the pelvic girdle is described. The vertebral structure and massiveness and morphological features of pubic bones provide a unique combination of features, allowing recognition of diagnostic characters. The new taxon comes from the Aptian–Albian deposits of the Khamryn-Us locality (Mongolia) and belongs to the latest Stegosauridae (Ornithschia).