Research explains why crocodiles have changed so little since the age of the dinosaurs

New research by scientists at the University of Bristol explains how a 'stop-start' pattern of evolution, governed by environmental change, could explain why crocodiles have changed so little since the age of the dinosaurs. Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago. There are also very few species alive today - just 25. Other animals such as lizards and birds have achieved a diversity of many thousands of species in the same amount of time or less. Prehistory also saw types of crocodile we don't see today, including giants as big as dinosaurs, plant-eaters, fast runners and serpentine forms that lived in the sea. In the new research, published today in the journal , the scientists explain how crocodiles follow a pattern of evolution known as 'punctuated equilibrium'. The rate of their evolution is generally slow, but occasionally they evolve more quickly because the environment has changed.