About 1.5 million years ago, two human species, Paranthropus boisei and Homo erectus, left intersecting footprints along a muddy lakeshore in northern Kenya, alongside tracks from various animals like antelopes, horses, and storks. These fossilized tracks, discovered at Koobi Fora, offer the first evidence that the two species coexisted in the same environment, raising questions about their interactions and potential competition for resources.

Paranthropus boisei, which lived from 2.3 to 1.2 million years ago, was shorter, standing around 137 cm tall, with large chewing muscles and massive molars, suited for processing tough vegetation. Their feet displayed ape-like features, including a divergent big toe. Homo erectus, a direct ancestor of modern humans, lived from about 1.89 million to 110,000 years ago, with larger brains and body proportions similar to ours.

In 2021, researchers discovered a long trackway of 12 footprints, approximately 26 cm long, belonging to an adult Paranthropus boisei. They also found three separate footprints of Homo erectus, which were smaller and possibly from a juvenile. These tracks, left in soft mud that hadn't dried, might have been made within hours or a few days of each other. It’s possible the two species saw each other but didn’t interact.

The findings suggest these species might have shared the landscape without direct competition for resources. Paranthropus boisei likely ate low-quality plants requiring extensive chewing, while Homo erectus was omnivorous, using tools to process meat. The two species lived in a resource-rich environment, despite the presence of dangerous animals like hippos and crocodiles.

Footprints provide valuable insights into ancient human behavior, anatomy, and locomotion. The Homo erectus footprints show a modern human-like shape, with a stiff foot and a walking gait that pushes off the toes, while Paranthropus boisei had a more flat-footed, ape-like walk with a more mobile big toe.

These two species occupied the same landscape for about 200,000 years, with Paranthropus boisei eventually going extinct, while Homo erectus spread beyond Africa and may have been a direct ancestor of modern humans. The discovery highlights the significance of these ancient environments, which were worth the risk of dangerous animals for our early ancestors.

Disclaimer: This image is taken from Reuters