Ancient footprints in Kenya reveal coexistence of Early Human Ancestors

Newly discovered footprints on the shores of Kenya’s Lake Turkana offer a rare glimpse into a moment in history from 1.5 million years ago, revealing the coexistence of two distinct early human ancestors.

The fossilized footprints, uncovered in 2021 at Koobi Fora, Kenya, were left by Homo erectus and Paranthropus boisei, two extinct species that shared the Turkana Basin. According to paleontologists, the tracks were likely made within hours or days of each other, suggesting these ancestors may have been aware of each other’s presence.

“This discovery captures an actual moment in time,” said Louise Leakey, paleontologist and co-author of the research published in Science. “It’s remarkable to think these individuals might have crossed paths or influenced one another’s lives.”

Scientists identified the two species by analyzing the anatomical differences in their footprints. Homo erectus, known for its more modern gait, walked with a heel-first stride similar to humans today. In contrast, Paranthropus boisei, while also walking upright, displayed a unique movement style, with greater flexibility in the big toe distinct from any known hominin species, according to co-author Erin Marie Williams-Hatala, a human evolutionary anatomist.

“These footprints reveal a previously unseen way of walking upright,” Williams-Hatala noted, adding that the anatomical differences hint at varied adaptations among early humans.

The findings highlight the complexity of the evolution of bipedalism, which allowed human ancestors to move on two feet. The process did not occur in a single event or follow a uniform path, researchers say.

“Our primate ancestors originally had feet adapted for grasping branches,” said Kevin Hatala, a paleoanthropologist at Chatham University. “Over time, human ancestors evolved feet suited for upright walking, but there wasn’t just one way this transformation unfolded.”

Paleontologist William Harcourt-Smith, who was not involved in the study, described the discovery as groundbreaking. “It shows there were different ways of being bipedal, offering a more complex picture of early human locomotion.”

The footprints serve as a powerful reminder of the coexistence and interactions between different species in the human evolutionary tree. “These individuals likely knew of each other’s presence,” Hatala explained. “They probably influenced each other in ways we’re only beginning to understand.”

This discovery adds to a growing body of research about human evolution, shedding light on the diverse paths that early humans took to adapt to their environments and walk upright.