Pre-dinosaur era burrow discovered in Antarctica

Pre-dinosaur era burrow discovered in Antarctica:

A burrow has been discovered in the ancient flood plain of a broad Antarctic river only a few million years after a mass extinction ended the Permian period.

The tunnel was preserved when a flood washed sand into it, forming a cast 35 centimetres deep and 16 cm wide — and even preserving claw marks scratched into the walls during excavation.

Palaeontologist Christian Sidor of the University of Washington thinks the den belonged to Thrinaxodon, a small badger-like reptile closely related to mammals.

A second candidate is a lizard-like reptile called Procolophon. Bones of both animals have been found in Antarctica and in South Africa.