Pliosauridae

Pliosauridae is a family of plesiosaurian marine reptiles from the Latest Triassic to the early Late Cretaceous (Rhaetian to Turonian stages). The family is more inclusive than the archetypal short-necked large headed species that are placed in the subclade Thalassophonea, with early, primitive forms resembling other plesiosaurs with long necks.

The largest thalassophonean pliosaurs reached , in length, with around a quarter of this length being the head. Thalassophonean pliosaurs represented the largest marine predators during their existence, spanning more than 80 million years.