Mystery Solved: A new study has discovered that footprints thought to have been made by bears were actually left by early humans millions of years ago. Evidence of a big toe and large heel in the fossilized impressions, discovered at a site in Tanzania in 1976, helped classify them as belonging to an unidentified bipedal hominin.
This discovery suggests that more than one of those species walked on two legs 3.7 million years ago, as separate footprints found at a nearby site at Laetoli have previously been identified as the earliest definitive evidence of hominin bipedalism.
The footprints were measured, photographed and scanned in 3D, showing that they had a large impression on the heel and big toe, which match a species of hominid. The researchers also conducted a video analysis of the behavior of the wild American black bear and found that the animal almost never walks on its hind legs.
“Through this research, we now have conclusive evidence from Site A footprints that there were different species of hominin walking bipeds in this landscape but in different ways on different feet,” explains Jeremy DeSilva, associate professor of anthropology at Dartmouth College. .
The findings are part of a growing body of evidence hinting at an underestimated diversity of hominids from this time period, the researchers concluded.
Referencia: McNutt, E.J., Hatala, K.G., Miller, C. et al. Footprint evidence of early hominin locomotor diversity at Laetoli, Tanzania. Nature (2021). https://doi.org/10.1038/s41586-021-04187-7
