Making Sense of the End-Ordovician Mass Extinction 

THIS ARTICLE discusses the End-Ordovician mass extinction, the second-most severe in the Earth's history. The difficulty with this extinction is that all the usual suspects are absent - no meteor craters, no vast pile of lava. 

I addition there was an accompanying diversification in life. Many of the life forms from the Cambrian were replaced. And there was a lot of glaciation about.

How can it be explained? The article gives one attempt. It uses the position of the Earth's magnetic pole during the period between 460 and 435 Ma. And it seems to have whizzed about rather quickly. The researchers have the hypothesis that the lithosphere rotated 50° relative to the Earth's axis. This requires a speed of 55cm per year!

Palaeogeographic reconstructions charting true polar wander and the synchronised movement of all continental masses between 460 and 440 Ma. Note the changes in the trajectories of lines of latitude on the Mollweide projections. The grey band either side of the palaeo-Equator marks intense chemical weathering in the humid tropics. Credit Jing et al. Fig 5.

The article discusses the affect this would have. Habitats zooming through different climate zones would kill off many species. Equally it would give the opportunity for new species to develop. (Sounds a bit like Brexit!).

Read the article and the academic article it is based on. You can get the pdf of the Nature article HERE.