An article published in the journal “Nature” shows a molecular and microstructural analysis of a fossil of Stenopterygius, a marine reptile that belonged to the order of ichthyosaurs and lived about 180 million years ago. A team of researchers examined a fossil found in the Holzmaden quarry in Germany of which various soft tissues also got fossilized. This allowed to find chemical traces consistent with blubber, fatty tissue similar to whale fat and other aquatic or semi-aquatic mammals’ fat, all warm-blooded species. The conclusion is that Stenopterygius was warm-blooded as well.