Syrmosaurus Maleev, 1952

HILL, ROBERT V., WITMER, LAWRENCE M. & NORELL, MARK A., 2003, A New Specimen of Pinacosaurus grangeri (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia: Ontogeny and Phylogeny of Ankylosaurs, American Museum Novitates 3395, pp. 1-30 : 4

(= Syrmosaurus Maleev, 1952 )

TYPE SPECIES: Pinacosaurus grangeri Gilmore, 1933b .

INCLUDED SPECIES: Type species and P. mephistocephalus Godefroit et al., 1999 .

AGE AND DISTRIBUTION:?Late Santonian– Late Campanian of Mongolia and People’s Republic of China.

REVISED DIAGNOSIS: Medium­sized ankylosaurid, attaining approximately 5 m in length, with skull longer than wide in adult; premaxillary beak edge not covered by secondary dermal ossifications; large, rostrally facing nares roofed by osteoderms; premaxillary struts define at least two additional openings in narial region, leading to an extensive premaxillary sinus; prominent, hornlike protuberances above orbit formed by lateralmost supraorbital bone; lacrimal incisure (marked pinching of snout in lacrimal region so that the orbits and narial region project laterally beyond the incisure); beak only slightly wider than distance between caudalmost maxillary teeth; quadrate not co­ossified with the paroccipital process; quadrate cotyla lying directly below caudal margin of orbit.

Pinacosaurus grangeri Gilmore, 1933b (= P. ninghsiensis Young, 1935 ;