Study suggests creatures might have been warm-blooded
Ancient marine reptiles, which cruised the seas while dinosaurs roamed the land, may have been warm-blooded, with some species able to maintain a body temperature as much as 20 degrees Celsius above that of the waters they swam in, a new study suggests.
The finding, reported in the June 11 Science, bolsters the notion that many marine reptiles had relatively high metabolic rates similar to those of modern-day tuna, says Christophe Lécuyer, an isotope geochemist at the University of Lyon 1 in Villeurbanne, France. And that warm-bloodedness played a big role in these creatures’ evolutionary success, he notes: As a group, marine reptiles such as ichthyosaurs and plesiosaurs were among the ocean’s top predators for more than 185 million years.
While the body temperature of a cold-blooded, or ectothermic, creature is the same as that of the animal’s environment, warm-blooded, or endothermic, creatures use internally generated heat to par