Some of thegiant reptileswho dominated themarine food chain during the time of the dinosaursthey might have been able tocontrol their own body temperatures. This is the conclusion reached by a team of French and Danish scientists after analyzing three extinct swimming reptiles, the main predators of the oceans more than 65 million years ago:ictiosaurios, plesiosauriosYmosasaurios.
The researchers explored the metabolic regime of the fossil remains of these reptiles and calculated the stable oxygen isotope compositions of their tooth enamel. Also, they compared them to fish that lived in the same environments. “The isotopic composition of phosphate oxygen in vertebrates depends on body temperature and the composition of ingested water. If marine reptiles and fish lived in the same body of water, the differences in isotopic composition will reflect their differences in body temperature “, explains Christophe Lecuyer, one of the study authors and a researcher at the University of Lyon 1 (France).
The results of the research, which is now published inScience, show that ichthyosaurs and plesiosaurs rthey regulated their body temperature “independently of that of sea water, which ranged between 12-2ºC (cold temperate climate) and 36-2ºC (tropical)”, Lecuyer emphasizes.
The ability to regulate body temperature allowed reptiles to conquer new marine environments at high latitudes where temperatures were weaker. According to the expert, this characteristic also provided them with “important energy reserves to be effective predators.”High metabolic rates aided in predation, deep diving, and fast swimming long distances.
