An artist’s depiction of Lucy, the world’s most famous Australopithecus africanus. (Credit: Greg Grabowski/Shutterstock)

In the savannah of southern Africa three million years ago, an early human species known as Australopithecus africanus roamed the tropical grasslands chomping on a diverse diet of fruits, leaves and roots. The hominins ate well when the land was ripe with bounty, but seasonal rains and lengthy dry spells meant food was often scarce.

Now an international team of research