There are tantalizing pieces related to this. One is that scientists are interested in finding iridium, it's relatively common in asteroids and comets but exceedingly rare in the Earth's crust. The famous mass extinction associated with an asteroid impact is the one that kills the non-flying dinosaurs at the Cretaceous Paleogene. Mike Benton: I don't think people look at tectonic movements directly as a cause of this. But whether they could have global effects... we know that volcanic eruptions always kill life.
Melvyn Bragg and guests discuss the devastating mass extinctions of the Late Devonian Period, roughly 370 million years ago, when around 70 percent of species disappeared. Scientists are still trying to establish exactly what happened, when and why, but this was not as sudden as when an asteroid hits Earth. The Devonian Period had seen the first trees and soils and it had such a diversity of sea life that it’s known as the Age of Fishes, some of them massive and armoured, and, in one of the iconic stages in evolution, some of them moving onto land for the first time. One of the most important theories for the first stage of this extinction is that the new soils washed into oceans, leading to algal blooms that left the waters without oxygen and suffocated the marine life.
The image above is an abstract group of the huge, armoured Dunkleosteus fish, lost in the Late Devonian Extinction
With
Jessica Whiteside
Associate Professor of Geochemistry in the Department of Ocean and Earth Science at the University of Southampton
David Bond
Professor of Geology at the University of Hull
And
Mike Benton
Professor of Vertebrate Paleontology at the School of Life Sciences, University of Bristol.