Two species of ancient human relatives crossed paths 1.5 million years ago. Fossilized footprints in Kenya captured the moment, according to a new study.

Newly discovered 1.5-million-year-old footprints reveal how two extinct human species crossed paths within hours of each other.

An international team of researchers said Thursday that they had found two sets of hominin footprints that were made about the same time on an ancient lake’s shore in present-day Kenya. It is, they said, a “fossil first” that offers proof different hominin species lived at the same time and space.

The footprints are the first clear evidence that the two hominin species shared a habitat, raising questions about whether their interactions shaped human evolution.

About 1.5 million years ago, individuals of two different species in the human evolutionary lineage trudged on a muddy lakeshore in northern Kenya, leaving behind intersecting trackways alongside the footprints of antelopes,

A set of footprints found at the site of Koobi Fora in Kenya reveals that our ancestor Homo erectus coexisted with a now-extinct bipedal hominin, Paranthropus boisei, 1.5 million years ago.

Two sets of fossilized footprints from early human species were made within a few hours of each other about 1.5 million years ago, researchers suggest