Imperial alumnus discusses rise and fall of ancient dinosaur-eating crocodiles

Fearsome ancient dinosaur-devouring crocodiles thrived on Earth until changes in the sea level affected their habitats, says an Imperial alumnus.

Dr Jon Tennant studied these creatures as part of his PhD in the Department of Earth Science and Engineering. He was exploring the biodiversity and the extinction of some tetrapods, which is a classification for all creatures with four limbs.

Dr Tennant, who is also a science communicator and children’s author, looked at some of the most fearsome tetrapods of them all – crocodilians. These creatures, which alligators and crocodiles are modern ancestors of, lived on Earth over one hundred million years ago in the deserts, coasts, oceans and even the artic regions of our planet. Some, like the Sarchosuchus, were the size of double-decker buses, and going by the fossil evidence, fed on dinosaurs, who were rival ‘apex’ predators.

Dr Tenant discovered in his research that changes in sea level, brought on by fluctuations in the climate and continent movements, changed the world of tetrapods like the Sarchosuchus forever. Now, he is embarking on a six-month exploration of the planet, including some of the regions where modern crocodilians live. Colin Smith caught up with Dr Tenant to talk about his favourite ancient crocodilians and how changes in early Earth impacted on their biodiversity.