Footprints Suggest Different Human Relatives Lived Alongside One Another The New York TimesThese two ancient human relatives crossed paths 1.5 million years ago Nature.comFootprints Reveal Two Early Human Species Walked the Same Lakeshore in Kenya 1.5 Million Years Ago Smithsonian MagazineFossil Footprints Suggest Two Early Human Species Crossed Paths within Hours Scientific AmericanRare footprints suggest two of our prehistoric ancestors may have met The Washington Post