Muddy footprints left on a Kenyan lakeside suggest two of our early human ancestors were neighbors some 1.5 million years ago.

Muddy footprints found beside Lake Turkana, Kenya reveal two ancient hominin species were once neighbors 1.5 million years ago.

Researchers discovered 1.5-million-year-old footprints in Kenya's Turkana Basin, revealing coexistence of Paranthropus boisei and Homo erectus. The prints, showing distinct walking patterns, provide direct evidence of the two species' interaction and environment,