The genus Archaeonectrus was proposed by Novozhilov (1964) for ‘Plesiosaurus’ rostratus, a species named by Owen (1865). By modern standards, Owen’s (1865) original description is rather inadequate. One notable characteristic of Archaeonectrus rostratus is the relatively small size of the limbs relative to its body. It has been classified as a pliosauroid, sometimes within the Rhomaleosauridae. Archaeonectrus rostratus is the type and only species of this genus.
Sinemurian, Lower Jurassic
Charmouth Mudstone Formation
Charmouth, Dorset, England
BMNH 38525, complete articulated skeleton including skull preserved in dorsal view