The ancient whales had four legs and shared their time between the land and the sea

Whales belong to the ocean, right? It may be true today, but cetaceans (whales, dolphins, porpoises) are actually from four-legged mammals that once lived on Earth. New research published in Current Biology reports the discovery in Peru of a brand new species of ancestral whale that rode land and sea, offering a glimpse of the strange course of our mammal friends.

We could think of them as two-legged, smooth ocean swimmers struggling to survive even in the Thames, but the whales are native to artiodactyls – land mammals inhabited more than 50 years ago.

Originally, the ancestors of whales resembled small deer with four toes, each ending in a small hoof. A fossilized "missing link" discovered in India suggests that the last whale precursors were put in the water in times of danger, but arrived on land to give birth and eat. They would spend a lot of time wading in shallow waters, looking for aquatic vegetation and invertebrates, and possibly small fish and amphibians.