Part 2: Around 66 million years ago an enormous asteroid barrelled into the earth and wiped out ichthyosaurs, pterosaurs, and dinosaurs*. Debate has raged back and forth as to whether the dinosaurs were already in decline before this mass extinction or were still going strong. This week, Susie and Rob are joined by Prof. Steve Brusatte to take a look at what vertebrates were doing just before the asteroid hit. In part 2 we discuss what would have happened if the asteroid had missed, Steve's new upcoming book, Jurassic World, and Nannotyrannus.

*except birds of course.

Widescreen artwork by Natalia Jagielska