In the Mesozoic era, about 250 to 65 million years ago a large number of reptiles populated the oceans. The most successful were the plesiosaurs, which existed for about the same time as the dinosaurs. Enlarged red blood cells ensured their survival. This was discovered by paleontologists at Bonn University and zoologist Kai R. Caspar from Duisburg-Essen University (UDE). The results can be read in the international bioscientific online journal PeerJ.
Click here for original story, Divers of the past: Plesiosaur research reveals rapid increase of blood cell size
Source: Phys.org