How climate change affected the shape of elephant teeth

Seeing elephants in the wild is a timelessly awe-inspiring experience. The fossil record shows that, 20 million years ago, proboscidean teeth looked completely different. Their tooth wear measurements from fossils revealed that, about 21 million years ago, the first increase in dietary uptake of grass was achieved by the primitive “gomphothere”-type proboscideans of Africa. Statistical testing of the data showed that the African environment began to get drastically more arid between 7 million and 5 million years ago, and this drove a vast increase in the rate of dental evolution in the lineage that gave rise to mammoths and modern elephants, as well as promoting the further spread of grasslands. This new dental form provided such an advantage that, around 3.6 million years ago, early elephants had outcompeted the last African gomphotheres into extinction.