Science Frontiers · natural-world

Filed by Dr. Vera Quark

Millions of years after animals first conquered land, some took an extraordinary evolutionary U-turn and returned to the water. Using machine learning and thousands of fossil measurements, Yale scientists have uncovered surprising clues about which prehistoric creatures truly became aquatic. Their findings suggest that Spinosaurus spent most of its life underwater, while some ancient marine reptiles previously thought to be fully aquatic actually spent considerable time on land.