Many of the teeth were eroded. This poor dental hygiene hints at a problem with their diet, says Zhang. “There was something wrong before Gigantopithecus’s extinction, and I think it comes from the food.”

The ape may have had to switch diet as the climate cooled and its preferred food – probably plants like bamboo – became rare. The teeth suggest it turned to less-nutritious fruit rich in enamel-eroding acids, says Zhang.

But fruit is good for most apes, says Kornelius Kupczik of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “Chimpanzees eat a lot of fruits that are extremely bitter or acidic to the human palate,” he says, yet their teeth don’t rot much.