There is something like 25 species of crocx. Most belong to the genus crocodyllus, which includes the nile crocodile and the salt water crocodile. A large amount of them belong to alligator and its close relative, the camen. And then there are a couple of gariols. So i said there's probably 25 because we're still trying to work out whether some of these species actually represent multiple species.
Melvyn Bragg and guests discuss the remarkable diversity of the animals that dominated life on land in the Triassic, before the rise of the dinosaurs in the Jurassic, and whose descendants are often described wrongly as 'living fossils'. For tens of millions of years, the ancestors of alligators and Nile crocodiles included some as large as a bus, some running on two legs like a T Rex and some that lived like whales. They survived and rebounded from a series of extinction events but, while the range of habitats of the dinosaur descendants such as birds covers much of the globe, those of the crocodiles have contracted, even if the animals themselves continue to evolve today as quickly as they ever have.
With
Anjali Goswami
Research Leader in Life Sciences and Dean of Postgraduate Education at the Natural History Museum
Philip Mannion
Lecturer in the Department of Earth Sciences at University College London
And
Steve Brusatte
Professor of Palaeontology and Evolution at the University of Edinburgh
Producer Simon Tillotson