Tianyulong

Tianyulong Temporal range: Early Cretaceous
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Ornithischia
Family:	Heterodontosauridae
Genus:	Tianyulong Xiao-Ting Zheng, Hai-Lu You, Xing Xu & Zhi-Ming Dong, 2009
Species
T. confuciusi X.-T. Zheng, H.-L. You, X. Xu & Z.-M. Dong, 2009 (type)

Tianyulong (from the Shandong Tianyu Museum of Nature where the holotype is housed) is a genus of heterodontosaurid dinosaur known to have a row of long filamentous integumentary structures on its back. The only species is T. confuciusi whose remains were discovered in Jianchang County, Western Liaoning Province, China, from a formation belonging to the Jehol group and dating from the Early Cretaceous.

The holotype consists of an incomplete skeleton preserving a partial skull and mandible, partial presacral vertebrae, proximal–middle caudal vertebrae, nearly complete right scapula, both humeri, the proximal end of the left ulna, partial pubes, both ischia, both femora, the right tibia and fibula and pes, as well as impressions of long, singular and unbranched filamentous integumentary structures. The holotype is from a subadult individual that probably measured 70 cm in length based on the proportions of the South African related genus Heterodontosaurus.

The filamentous integumentary structures are preserved on three areas of the fossil: in one patch just below the neck , another one on the back , and the largest one above the tail. The hollow filaments are parallel to each other and are singular with no evidence of branching. They also appear to be relatively rigid, making them more analogous to the integumentary structures found on the tail of Psittacosaurus than to the proto-feather structures found in avian and non-avian theropods.

Reference

Tianyulong - a fuzzy dinosaur that makes the origin of feathers fuzzier