Fossil footprints baffle scientists

study co-author and paleoanthropologist Jeremy Desilva, of Dartmouth College, New Hampshire.

He and other researchers returned to the site in 2019 and used Leakey’s original maps to locate the enigmatic prints, preserved in a layer of volcanic ash that had cooled and hardened.

Co-author Ellison Mcnutt of Ohio University studied the foot mechanics of black bear cubs at a wildlife rescue centre in New Hampshire to see whether a small bear walking on its hind legs could leave similar footprints. She concluded that the fossil footprints were not left by bears.

Other factors, such as the spacing of the footprints, led the study authors to conclude that that the prints were left by a previously unknown species of a very early human ancestor.

If two different species were walking upright on the landscape at the same time, this suggests different simultaneous experiments in bipedalism – and complicating the conventional view of human evolution as strictly linear. –AP