You all remember the Laetoli footprints from Tanzania: footprints from what were probably three individuals of Australopithecus afarensis, made 3.6 million years ago as they walked across soft volcanic ash. Those proved indubitably that our early ancestors were fully bipedal, and were a poignant snapshot of hominins long gone.
Scientific American now reports on another such finding: a group of footprints (also in Tanzania) from 18 individuals of Homo sapiens walking together on the shores of Lake Natron. They’re dated at 120,000 years ago. This discovery hasn’t yet been published, but was announced two days ago by Brian Richmond of George Washington University at the latest meeting of the Paleoanthropology Society. As Sci Am reports, there were other human footprints as well, but one set seems to have been left by a social band of hominins:
The other group of prints, however, were made by 18 individuals walking together to the west.
To learn more about the these early travelers, Richmond and his colleagues compared the fossil footprints to a set of prints obtained experimentally from modern-day men and women from Ileret, Kenya, moving at a variety of speeds. Based on these measurements, the team concluded that the ancient human group was composed of men, women and children, with more women than men.
Now we already knew from fossils that H. sapiens was fully bipedal, but the paper may shed rare light on early human society. Was 18 the size of this early human social group?
The Scientific American report didn’t have any photos, but I dug one up from the website of Dr. Cynthia Liutkus of Appalachian State University, who works on the Natron footprints:
Judging by the length and width, if this were a male he’d wear a size 7 D cowboy boot.