RHOMALEOSAURIDAE
Sauropterygia > Eosauropterygia > Eusauropterygia > Plesiosauria > Pliosauroidea> Rhomaleosauridae
Discussion
This plesiomorphic ('primitive') group of plesiosaurs is critically understudied. Rhomaleosaurids are undergoing revision - I am studying this group for my Ph.D project at University College Dublin. All rhomaleosaurids share a rather large typically pliosaur head with a reasonably long neck composed of about 28 vertebrae. The group ranges from the Lower Jurassic to the Lower Cretaceous.