Two ancient human relatives crossed paths 1.5 million years ago

Some 1.5 million years ago, two ancient hominin species crossed paths on a lake shore in Kenya. Their footprints in the mud were frozen in time and lay undiscovered until 2021. Now, analysis of the impressions reveals that they belonged to Homo erectus, a forebear of modern humans, and the more distant relative Paranthropus boisei. The two individuals walked through the lake area within hours or days of each other — leaving the first direct record of different archaic hominin species coexisting in the same place.