Mystery of Darwin’s strange mammals finally solved

For 180 years, scientists tried to figure out where to place Toxodon platensis (left) and Macrauchenia patachonica (right) belonged in the mammalian evolutionary tree. Only recently have they found the answer.

What were these mysterious mammals: one looking like a hippo-rhino-rodent hybrid and another resembling a humpless camel with an elephant’s trunk?

Ever since British naturalist Charles Darwin found their fossils in South America and brought them back to England about 180 years ago, scientists have been scratching their heads just exactly where to place these odd beasts that went extinct just 10,000 years ago on the mammal family tree.