Tricleidus is an extinct genus of cryptoclidid plesiosaur known from only specimen from the middle Jurassic of United Kingdom. It was first named by Andrews in 1909 and the type species is Tricleidus
Colymbosaurus is a genus of cryptoclidid plesiosaur from the Middle-Late Jurassic of the UK and Svalbard, Norway. There are two currently recognized species, C. megadeirus and C. svalbardensis.
Colymbosaurus scapula and coracoids that were previously assigned to C. trochantericus