Colymbosaurus trochanterius (Owen , 1840)
Tail vertebra from a Plesiosaur Matrix free. Nice preservation and detail. Rare find.
Jurassic, Kimmeridge Clay. Re-worked into Cretaceous, Aptian, Faringdon Sponge Gravels.
Wicklesham Pit, Faringdon, Oxfordshire..
Vertebra : 2.5 cm long.