Fossil Footprints Offer New Insight into Upright Walking

Five fossilised Footprints in volcanic ash 3.66 million years old in Tanzania are giving scientists new insight on a landmark in human evolution – upright walking – while showing that its origins are more complicated than previously known.Researchers said on Wednesday a thorough new examination of the tracks, nearly half a century after their initial discovery, has shown that they were made not by a bear, as once believed, but by a hominin – a species in the human lineage – and possibly a previously unknown one.

Bipedalism walking on two feet – is a hallmark of humankind, but scientists are still putting together the puzzle pieces on how and when it began.The trackway was found in 1976 at a site called Laetoli – a stark landscape northwest of the Ngorongoro Crater in northern Tanzania – about a 1.6 km from two sets of fossil Footprints found two years later.

Those found in 1978 have been attributed to Australopithecus afarensis, a hominin exemplified by the famous skeleton discovered in Ethiopia dubbed “Lucy”. The study determined that the various Laetoli tracks made within days, hours or possibly minutes of one another in the same ash layer – were created by two different hominin species.

Ellie McNutt of Ohio University’s Heritage College of Osteopathic Medicine, lead author of the study published in the journal Nature, noted that the Laetoli trackways represent the oldest unequivocal evidence of bipedal locomotion in the human fossil record.