Ulansuhai Formation Explained

The Ulansuhai Formation is a geological formation in Inner Mongolia, north China. Dinosaur remains are among the fossils that have been recovered from the formation.^[1]

The Ulansuhai Formation has traditionally been considered to date to the Aptian-Albian stages of the Lower Cretaceous, due to similarities between the Ulansuhai fauna and known Aptian formations.^[1] However, radiometric dating done on underlying formations has shown this to be incorrect. Due to the age of underlying rocks, the Ulansuhai Formation cannot be older than the Turonian stage of the Late Cretaceous, about 92 Ma.^{[2] [3]}

Fossil content

Dinosaurs

The carcharodontosaurid Shaochilong and ankylosaurid Gobisaurus were initially reported from this formation, but actually derive from the Miaogou Formation, which has outcrops nearby.^[4]

Dinosaurs
Taxa	Presence	Description	Images
Chilantaisaurus tashuikouensis		A primitive coelurosaurian[5] ."Fragmentary postcranial skeleton."[6]
Sinocephale bexelli[7]		A pachycephalosaurid, known from now lost skull fragments. Formerly Troodon bexelli.
Sinornithomimus dongi[8]		An ornithomimid. "[Fourteen] skeletons, juvenile to adult."[9]
Indeterminate Iguanodontian

Testudines

Turtles!Taxa!Presence!Description!Images

Kuhnemys maortuensis[10]

A pantrionychid turtle

Ostracods

See also

• List of dinosaur-bearing rock formations

Notes and References

1. Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. .
2. Kobayashi, Y., and Lu, J.-C. (2003). "A new ornithomimid dinosaurian with gregarious habits from the Late Cretaceous of China." Acta Palaeontol. Pol., 48: 235–259.
3. Benson, R.B.J. and Xu, X. (2008). "The anatomy and systematic position of the theropod dinosaur Chilantaisaurus tashuikouensis Hu, 1964 from the Early Cretaceous of Alanshan, People’s Republic of China." Geol. Mag., 145: 778–789.
4. Hao . Mingze . Li . Zhiyu . Wang . Zhili . Wang . Shuqiong . Ma . Feimin . Qinggele . King . J. Logan . Pei . Rui . Zhao . Qi . Xu . Xing . 2024-10-24 . A new oviraptorosaur from the Lower Cretaceous Miaogou Formation of western Inner Mongolia, China . . en . 106023 . in press . 10.1016/j.cretres.2024.106023.
5. Benson, R.B.J. and Xu, X. (2008). "The anatomy and systematic position of the theropod dinosaur Chilantaisaurus tashuikouensis Hu, 1964 from the Early Cretaceous of Alanshan, People’s Republic of China." Geol. Mag., 145: 778–789.
6. "Table 4.1," in Weishampel, et al. (2004). Page 73.
7. Evans. David. Brown. Caleb M.. You. Hailu. Campione. Nicolás E.. 2021. Description and revised diagnosis of Asia's first recorded pachycephalosaurid, Sinocephale bexelli gen. nov., from the Upper Cretaceous of Inner Mongolia, China. Canadian Journal of Earth Sciences. e-First. 10. 981–992. 10.1139/cjes-2020-0190. 244227050.
8. Kobayashi and Lu. Yoshitsugu and Jun-Chang. 2003. A new ornithomimid dinosaur with gregarious habits from the Late Cretaceous of China. Acta Palaeontologica Polonica. 48. 2. 235–259.
9. "Table 5.1," in Weishampel, et al. (2004). Page 138.
10. S.-Y. Hu. 1964. [Carnosaurian remains from Alashan, Inner Mongolia]. Vertebrata PalAsiatica. 8(1):42-63