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 GoswamiResearch Leader in Life Sciences and Dean of Postgraduate Education at the Natural History Museum

Philip MannionLecturer in the Department of Earth Sciences at University College London

And

Steve BrusatteProfessor of Palaeontology and Evolution at the University of Edinburgh

Producer Simon Tillotson