Muddy footprints left on a Kenyan lakeside suggest two of our early human ancestors were nearby neighbors some 1.5 million years ago. The footprints were left in the mud by two different species “within a matter of hours, or at most days,” said paleontologist Louise Leakey, co-author of the research published Thursday in the journal Science.
Scientists previously knew from fossil remains that these two extinct branches of the human evolutionary tree – called Homo erectus and Paranthropus boisei – lived about the same time in the Turkana Basin. But dating fossils is not exact. “It’s plus or minus a few thousand years,” said paleontologist William Harcourt-Smith of Lehman College and the American Museum of Natural History in New York, who was not involved in the study.
Yet with fossil footprints, “there’s an actual moment in time preserved,” he said. “It’s an amazing discovery.”