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 relatively few species alive today – just 25, as far as is known.

Much greater diversity in the past

Other groups of creatures such as lizards and birds have achieved a diversity of many thousands of species during the same period of time or less. But it appears that crocodiles have gone backwards, in terms of the number of forms and the diversity existing within this group of reptiles. Prehistory records various types of crocodile that we don’t see today, including giants as big as dinosaurs, some that were at home on land, serpentine marine forms and even plant-eaters!