Ordovician-Silurian true polar wander as a mechanism for severe glaciation and mass extinction.

The Ordovician-Silurian transition experienced severe, but enigmatic, glaciation, as well as a paradoxical combination of mass extinction and species origination. Here we report a large and fast true polar wander (TPW) event that occurred 450-440 million years ago based on palaeomagnetic data from South China and compiled reliable palaeopoles from all major continents. Collectively, a ~50˚ wholesale rotation with maximum continental speeds of ~55 cm yr is demonstrated.