In Our Time: Science

The Permian-Triassic Boundary

42:10 | Jun 28th, 2007

Melvyn Bragg and guests discuss the Permian-Triassic boundary. 250 million years ago, in the Permian period of geological time, the most ferocious predators on earth were the Gorgonopsians. Up to ten feet in length, they had dog-like heads and huge s...Show More