Hyphalosaurus

Fossil of Hyphalosaurus baitaigouensis in Hong Kong Science Museum.

• Jehol Group, Liaoning, China, Asia

Hyphalosaurus is the most common Choristodere the Jehol biota. He lived in the Lower Cretaceous.

Features

Hyphalosaurus was 116 cm long, had a small skull with numerous needle-like teeth in the pointed snout, 13 rows of ribs, twenty rows belly ribs, 19 vertebrae, 16-17 dorsal three sacral vertebrae, and 55 tail vertebrae. His neck and his tail was very long, 20 cm in the case of the neck. Generally Hyphalosaurus was well adapted to a life in water and fed on fish. In fact fish of the genus Lycoptera were discovered in the vicinity of the mouth of a Hyphalosaurus instance on a stone slab.

Species

There are known two types:

• Hyphalosaurus lingyuanensis GAO, TANG, WANG 1999 ( Syn: Sinohydrosaurus lingyuanensis LI, ZHANG, JI, 1999) and
• Hyphalosaurus baitaigouensis JI et al., 2004.