Credit: Mike Benton, University of Bristol. Animal images are by Nobu Tamura, Wikimedia
Caption: The origin of endothermy in synapsids, including the ancestors of mammals. The diagram shows the evolution of main groups through the Triassic, and the scale from blue to red is a measure of the degree of warm-bloodedness reconstructed based on different indicators of bone structure and anatomy.
Mammals and birds today are warm-blooded, and this is often taken as the reason for their great success.
University of Bristol palaeontologist Professor Mike Benton, identifies in the journal Gondwana Research that the ancestors of both mammals and birds became warm-blooded at the same time, some 250 million years ago, in the time when life was recovering from the greatest mass extinction of all time.
The Permian-Triassic mass extinction killed as much as 95 per cent of life, and the very few ...