Siluosaurus

Siluosaurus; Temporal range: Early Cretaceous, 130–112 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Neornithischia
Genus:	†Siluosaurus; Dong, 1997
Species:	†S. zhanggiani
Binomial name
	†Siluosaurus zhanggiani; Dong, 1997

Siluosaurus (meaning "Silu (Chinese for Silk Road, referring to the discovery location) lizard")^[1]is a genus of ornithischian dinosaur from the Barremian-Albian-age Lower Cretaceous Xinminbao Group of Gansu, China. It is based on the specimen IVPP V.11117 (1-2), which consists of two teeth. It is an obscure genus, with no papers doing more than mentioning it since it was described in 1997.^[1] The type species is S. zhanggiani.^[1]

History

The holotype teeth of Siluosaurus were recovered during the 1992 Sino-Japanese Silk Road Dinosaur Expedition in the lower portion of the Xinminbao Group. One tooth, seven millimetres long, was from the upper beak (premaxilla), and the other, 3.7 millimetres high, was from the cheek region of the upper jaw (maxilla). Dong Zhiming, who named the genus in 1997, suggested that it was a hypsilophodontid, and described the teeth as the smallest ornithopod teeth yet known. The type species is Siluosaurus zhanggiani. The specific name honours Zhang Qian, the Chinese diplomat who reconnoitred the Silk Road in the second century B.C.^[1] It was regarded without comment as a dubious name in the most recent review of basal ornithopods,^[2] a not-uncommon fate for dinosaur names based on teeth. Fonseca et al. (2024) recovered this genus as an indeterminate member of Cerapoda in their supplementary material.^[3]

Paleobiology

As a hypsilophodontid or other basal ornithopod, Siluosaurus would have been a bipedal herbivore. Its size has not been estimated, but as most adult hypsilophodonts were 1–2 meters (3.3–6.6 ft) long,^[2] this genus would have been of similar to smaller size, based on Dong's comments.

References

^ ^a ^b ^c ^d Zhiming, Dong (1997). "A small ornithopod from Mazongshan area, Gansu Province, China". In Dong Zhiming (ed.). Sino-Japanese Silk Road Dinosaur Expedition. Beijing: China Ocean Press. pp. 24–26. ISBN 7-5027-4298-0.
^ ^a ^b Norman, David B.; Sues, Hans-Dieter; Witmer, Larry M.; Coria, Rodolfo A. (2004). "Basal Ornithopoda". In Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.). The Dinosauria (2nd ed.). Berkeley: University of California Press. pp. 393–412. ISBN 0-520-24209-2.
^ Fonseca, A. O.; Reid, I. J.; Venner, A.; Duncan, R. J.; Garcia, M. S.; Müller, R. T. (2024). "A comprehensive phylogenetic analysis on early ornithischian evolution". Journal of Systematic Palaeontology. 22 (1). 2346577. Bibcode:2024JSPal..2246577F. doi:10.1080/14772019.2024.2346577.