Between 2 million and 3 million years ago, humans appeared in Africa — but identifying them in the fossil record is turning out to be surprisingly difficult. For 60 years, the earliest known human species has also been one of the most mysterious. Homo habilis was added to our family tree in 1964. But it’s long been unclear exactly what the ancient species, which lived between about 2.4 million and 1.65 million years ago, looked like. Read more
