Ancient human footprints reveal multiple species interaction in Kenya

The discovery at Koobi Fora, a muddy lakeshore in northern Kenya, revealed that two distinct species of humans, Paranthropus boisei and Homo erectus, walked side by side around 1.5 million years ago, with their footprints mixed in with antelopes, horses, warthogs, massive storks, and other creatures.

As reported by Reuters, in 2021, the footprints were uncovered by the researchers near Lake Turkana.

Based on their form and method of movement, they were able to pinpoint a single, lengthy trackway of twelve footprints, each measuring around 10.25 inches (26 cm) in length. They were all ascribed to an adult Paranthropus boisei individual.

Three isolated footprints, somewhat perpendicular to the main trackway, mirrored those of modern humans and ranged in length from 8 to 9.25 inches (20.5-23.5 cm).

Two were complete enough to be identified as probably young Homo erectus. It was more difficult to reliably designate the third.

“The fossil footprints provide us a clear picture of that instant in time, 1.5 million years ago. The different human ancestors may well have passed by each other, wading in the shallow water, possibly hunting and gathering,” said paleoanthropologist Louise Leakey, director of the Koobi Fora Research Project and co-author of the study published on Thursday in the journal Science.

The mud had never dried and cracked, and the trackways seemed to have been abandoned within a few hours or days, according to the researchers. It’s also possible that the people may have even seen one another. No indication of interaction was found.

“We think that these individuals, these two species that were there, probably would have been aware there were members of another species nearby. They would have seen each other and recognized each other as different species, which raises questions about what those interactions would have been like,” Kevin Hatala, an associate professor of biology at Chatham University and a lead author of the research, stated.

This species of humans according to scientists lived in East Africa between approximately 2.3 and 1.2 million years ago. It is one of the species in the genus Paranthropus, which is often referred to as “robust australopithecines” due to their adaptations for heavy chewing.

The Paranthropus boisei is not considered a direct ancestor of modern humans but rather a close relative that represents a side branch of the hominin evolutionary tree. Its lineage eventually went extinct.

The Homo erectus is an extinct hominin species that lived between approximately 1.9 million and 110,000 years ago. It is one of the most successful and widespread early human species, believed to have originated in Africa before dispersing to Asia and possibly Europe.

Homo erectus is prominently connected with the Acheulean tool culture, which is distinguished by bifacial hand axes and other stone tools that represent substantial technological advancements over previous Oldowan implements.

Evidence implies that H. erectus utilized tools to hunt, kill animals, and prepare plant resources.