But finding a nearly complete fossil was unheard of. "You find a vertebra here, a chunk of a skull there ... beginning with Pakicetus about 56 million years ago. By the time baleen whales emerged ...

But we know for certain that this back-to-the-water evolution did occur, thanks to a profusion of intermediate fossils that have ... The ear region of its skull is more specialized for underwater ...

He painstakingly removed a fossil skull from this material. A few months later, on 7 February 1925, he published his description of what he argued was a new hominin species, Australopithecus africanus ...