Hydrorion

Hydrorion
Temporal range: Lower Jurassic,
Skeleton
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Sauropterygia
Order: Plesiosauria
Family: Microcleididae
Genus: Hydrorion
Großmann, 2007
Type species
Hydrorion brachypterygius
Synonyms
  • Microcleidus brachypterygius von Huene, 1923
  • Plesiosaurus brachypterygius (von Huene, 1923)

Hydrorion (meaning 'water hunter') is a genus of plesiosaur from the Toarcian Age of the Lower Jurassic. It is only known from multiple specimens, all discovered in the Posidonia Shale of south-western Germany. The only species of Hydrorion is H. brachypterygius, which was originally described as a species of Plesiosaurus and then Microcleidus. It was a relatively small plesiosaur, with the largest specimen measuring 4 m (13 ft) long.