Climate cooling caused decline in crocodiles

Fluctuating sea levels and global cooling caused a significant decline in the number of <g data-gr-id="12">crocodylian</g> species over millions of years, a new study has found. Crocodylians include present-day species of crocodiles, alligators, caimans and gavials and their extinct ancestors.

They first appeared in the Late Cretaceous period, approximately 85 million years ago, and the 250 million year fossil record of their extinct relatives shows a diverse evolutionary history.

Extinct crocodylians and their relatives came in all shapes and sizes, including giant land-based creatures such as Sarcosuchus, which reached around 12 metres in length and weighed up to eight metric tonnes. <g data-gr-id="14">Crocodylians</g> also roamed the ocean - for example, <g data-gr-id="13">thalattosuchians</g> were equipped with flippers and shark-like tails to make them more agile in the sea. Agencies