The Ulansuhai Formation () is a geological

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

in Inner Mongolia, north China. Dinosaur remains are among the fossils that have been recovered from the formation.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. . The Ulansuhai Formation has traditionally been considered to date to the

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...

stages of the

Lower Cretaceous Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eight ...

, due to similarities between the Ulansuhai fauna and known Aptian formations. However,

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

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 The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by t ...

stage of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

, about 92 Ma.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.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.

Fossil content

Dinosaurs

Testudines

Ostracods

References

{{Reflist Geologic formations of China Upper Cretaceous Series of Asia Cretaceous China Turonian Stage Paleontology in Inner Mongolia

Fossil content

Dinosaurs

Testudines

Ostracods

See also

References