Past Time

Whales are spectacularly specialized mammals that seem perfectly adapted to their marine habitat. Plenty of other mammals have gone back to the water, but whales take it to a whole new level. No back legs, weird ear bones, noses on top of the head. What could the land-based ancestor of whales possibly looked like? Is there a fossil record of walking whales? In this episode we discover whales belong to the hooved animal group called Artiodactlys and their closest relatives, according to molecular comparisons, are hippos! But hippos and extinct fossil whales don't look very much alike. How did paleontologists, like our guest Dr. Marueen O'Leary, figure out the origins of whales, and how will they figure out the origins of hippos? As always, there are always more questions to answer when we start digging into the fossil record!