[D] Wannanosaurus yansiensis [Su] [sG] [T]
Describer
Hou, 1977
Time
Cretaceous Late Campanian
Classification
Ornithischia Genasauria Cerapoda Marginocephalia Pachycephalosauria Homalocephalidae
Diet
Herbivore
Fossilsite
Red Sandstones of the Late Cretaceous upper member of the Xiaoyan Formation, at the town of Yansi, Shexian Co., Anhui Province, China
Length
0,6 meter
Info
Genus - Typespecies - Skull
Partial skull roof, mandible, fragments of postcranium. (Holotype IVPP V4477) and associated vertebrae and limb bones of a second individual found nearby (Hou, 1977). Wannanosaurs had a flat dorsal skull table with relatively large supratemporal fossae. Diagnostic features include the low, fan-shaped dentary crowns with a marked median eminence on the lateral crown surface and the extreme flexure of the humerus.
The skull of Wannanosaurs yansiensis is fragmentary but very small. Nevertheless it probably represents an adult individualjudging from the obliterated sutures on the skull roof. The humerus is strongly bowed.
Type
Right posterior skull cap, left jugal, complete left mandible with seven relatively, complete teeth, pair of femora, right tibia, a portion of illium, and a single cervical vertebrae. Field No. 70101.2; IVPP V4447
Paratype
A pair of femora, single left tibia and fibula, partial pelvic girdle, a portion of right pes with three claws, and six caudal vertebrae. Field No. 70101.1; IVPP V4477.1
A relatively small and primitive pachycephalosaurid with a well-developed supratemporal fenestra. The cranial roof is completely flattened the thickest portion of the top of the frontoparietal is most posterior where it is also relatively well projected, osseous tuberosities are small and densely packed the partial and squamosal are notposteriorly projected and the occiput and quadrate are sligthly anteroventrally oblique. Mandibular dentition is long exceeding half the length of the mandible the posterior mandible is thin and weak, maintains ventral curvature, a broad and low surface, and a distinct retroarticular process. Dention is dentoculated. The forelimb is short and the humerus is half the length of the femur or shorter.
Source: Polyglot Paleontologist