Two pre-human species could have lived together 1.5 million years ago

A discovery in Kenya has revealed that Homo erectus and Paranthropus boisei, two different species of hominins, were reported to have coexisted 1.5 million years ago. According to a study published Thursday in the journal Science, the footprints were discovered in 2021 at Koobi Fora near Lake Turkana. These findings suggest that these two species not only shared the same environment, but may also have interacted with each other. The team, led by Kevin Hatala, a paleoanthropologist from the University of Chatham, analyzed a 26-meter-long trail of fossilized footprints.

Using advanced 3D imaging techniques, researchers identified tracks of individuals with different foot shapes and walking patterns. According to one source, it was concluded that the footprints with high arches and footprints were left by Homo erectus, whose body structure is very similar to that of modern humans. In contrast, the flatter footprints, characterized by deeper forefoot impressions, were attributed to Paranthropus boisei, known for its robust build and divergent big toe.

According to the studythe footprints provided detailed insight into the anatomical differences between the species. A single trackway contained a dozen prints of a P. boisei individual, whose foot size was equivalent to a modern American men’s size 8.5.

Meanwhile, H. erectus footprints were smaller, corresponding to shoe sizes between women’s size 4 and men’s size 6. Jeremy DeSilva, a paleoanthropologist from Dartmouth College, told LiveScience states that this discovery provides a rare glimpse into their locomotion and potential behavioral dynamics.

Implications for humanoid interaction

Hatala told the publication that these species likely recognized each other as different, drawing comparisons to the interactions observed between chimpanzees and gorillas today. Zach Throckmorton, a paleoanthropologist from Colorado State University, reportedly highlighted that the stability of the big toe, evident in H. erectus, is a crucial adaptation for walking and running.

The overlapping tracks, made within hours of each other, suggest these species shared a landscape that was closer together than previously thought. Although their precise interactions remain speculative, the discovery opens new avenues for understanding early human evolution.