Fossil footprints in northern Kenya show that two different kinds of early humans lived together 1.5 million years ago.
Paranthropus boisei, with its strong jaws, and Homo erectus, more like modern humans, shared the same area.
This amazing discovery provides solid proof of these species' coexistence, unlike previous assumptions based on bones.
The find sparks new questions about their daily lives, potential interactions and competition for resources.