Gorgonopsian Skull (IMAGE) University of Washington Caption The skull of a gorgonopsian, a distant mammal relative and top predator during its pre-dinosaur era about 255 million years ago. This fossil was collected in 2009 in Zambia. Credit Christian Sidor/University of Washington Usage Restrictions Image credit required. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.