Plesiosaurs of Europe

Thalassiodracon (tha-LAS-ee-o-DRAY-kon) is an extinct genus of plesiosauroid from the Pliosauridae that was alive during the Late Triassic-Early Jurassic (Rhaetian-Hettangian) and is known exclusively from the Lower Lias of England. The type and only species, is Thalassiodracon (Plesiosaurus) hawkinsii (Owen, 1838).

Lagenanectes is a genus of elasmosaurid plesiosaur from the Lower Cretaceous, found in Lower Saxony, Germany. The only species, Lagenanectes richterae, was first described in 2017, and is regarded as one of the best-preserved plesiosaur fossils from this geological age in Europe. Lagenanectes is one of the earliest elasmosaurids. The holotype is an incomplete skeleton, comprising large parts of the skull, some neck and tail vertebrae as well as ribs and part of the limbs. A length of about 8 meters (26 feet) has been estimated.

species of reptile (fossil)

Ophthalmothule (meaning "eye of the north"), was a cryptoclidid plesiosaur dating to the latest Volgian (around the Jurassic-Cretaceous boundary), found in the Slottsmøya Member Lagerstätte of the Agardhfjellet Formation in Spitsbergen. The type species is O. cryostea.

Bobosaurus is an extinct genus of sauropterygian reptile related to plesiosaurs. It is based on the holotype MFSN 27285, a partial skeleton found in early Carnian-aged rocks (early Late Triassic) of the Rio del Lago Formation, northeastern Italy. Bobosaurus was named in 2006 by Fabio M. Dalla Vecchia and the type species is B. forojuliensis. It may be a pistosaurid, or closer to Plesiosauria. A recent cladistic analysis found it to be a more basal pistosaur. It was a relatively large animal, with more than in length.

Alexeyisaurus is an extinct genus of possible plesiosaur known from the upper Triassic (lower-middle Norian age) of Wilczek Formation, Wilczek Land, of Franz Josef Land, Russia. It was first named by A. G. Sennikov and M. S. Arkhangelsky in 2010 and the type species is Alexeyisaurus karnoushenkoi. While considered an elasmosaur in the initial publication, it has been described as a "partial, poorly preserved, and undiagnostic sauropterygian skeleton" in subsequent publications.