Despite their giant size, the oldest pliosaurs had many teeth, indicating they had a diet of fish. But over time they developed fewer, stronger teeth suggesting they evolved to hunt large prey such as big fish and other marine reptiles. Just like many of today’s predators, pliosaurs probably disabled their prey and allowed them to weaken through blood loss before going in for the kill.
The Weymouth Bay pliosaur, one of the most complete and best preserved skulls ever found, has provided new insights into our understanding of how these enormous animals evolved. Giant pliosaurs were first found in the UK in the early 1800s, but most fossils were fragmentary, so their species diversity has been uncertain.
One of the most significant finds is that the genus Pliosaurus appears to have developed a highly effective body plan that remained little changed for millions of years. During that time, just a handful of species evolved and this is unlike most top predators in the fossil record which reach dominance but were then typically swiftly replaced by different forms.
The research has been undertaken by a team of vertebrate palaeontologists from Oxford, Bristol and Cambridge universities and with Leicester, Nottingham and the Sedgwick (Cambridge) museums together with independent researchers.