Hyphalosaurus baitaigouensis Ji et al., 2004

Hyphalosaurus baitaigouensis Ji et al., 2004
Lower Cretaceous
Jinzhou
Liaoning province
PR China

Length 8cm / 3"

In January 1999, two new choristoderans - aquatic living diapside reptiles - from the Jehol biota (lower cretaceous of Liaoning , China) were described by the "Institute of Vertebrate Paleontology and Paleoantropology" (IVPP) and by the "Beijing Natural History Museum" (BVC) under the names Sinohydrosaurus lingyuanensis Li et al., 1999 und Hyphalosaurus lingyuanensis Gao et al., 1999. It turned out that both institutes independently described slab and counterslab of the same individuum.
H. lingyuanensis is the valid name, this description was published slightly earlier - just by a couple of days.

This is a hatchling, adult Hyphalosaurs can reach almost 1.5m in length.

Hyphalosaurus is often faked and sold under different names.

Lit.:
Smith, J. and Harris J. (2001): A TAXONOMIC PROBLEM CONCERNING TWO DIAPSID GENERA FROM THE LOWER YIXIAN FORMATION OF LIAONING PROVINCE, NORTHEASTERN CHINA. Journal of Vertebrate Paleontology 21(2):389–391, June 2001.

Hou, L. et al.(2009): Implications of flexible-shelled eggs in a Cretaceous choristoderan reptile. Proc. R. Soc. B doi:10.1098/rspb. 2009.2035, Published online

Gao, K. and Ksepka, D. (2008): Osteology and taxonomic revision of Hyphalosaurus (Diapsida: Choristodera) from the Lower Cretaceous of Liaoning, China. J. Anat. (2008) 212, pp 747–768