2 Pre-Human Species Coexisted 1.5 Million Years Ago, Footprints Suggest

Scientists discovered two muddy footprints on a Kenyan lakeside that hint at possible interactions between our ancestors some 1.5 million years ago.

Researchers have examined two fossil footprints in Kenya that seem to be of different pre-human species left in the mud “within a matter of hours, or at most days,” said paleontologist Louise Leakey, co-author of the research published in the journal Science. 

This suggests that the two species—identified as Homo erectus and Paranthropus boisei—might have interacted with each other. 

“I would expect the two species would have been aware of each other’s existence on that landscape, and they probably would have recognized each other as being ‘different,’” Kevin Hatala, study co-author and paleoanthropologist at Chatham University in Pennsylvania, told Live Science.

“They probably saw each other, probably knew each other was there, and probably influenced each other in some way,” Hatala added, per AP News.

Hatala and his team of researchers analyzed the footprints to determine their shape and potential foot movements, which hint at the type of species that left the prints behind. They were then able to pinpoint the two separate species each belonged to.

This discovery raises further questions about how our ancestors behaved in relation to one another.

“It is fascinating to think about what they would have thought when they saw each other, and how they would have interacted,” Hatala told Live Science.