for National Geographic News
Researchers discovered the rock-hard hyena dung near the Sterkfontein caves, where many early human ancestor fossils have been found.
Each white, round fossil turd, or coprolite, is roughly 0.8 inch (2 centimeters) across. They were found embedded in sediments 195,000 to 257,000 years old.
Until now, the oldest known human hair was from a 9,000-year-old Chilean mummy.
The sizes and shapes of the coprolites and their location suggest they came from brown hyenas, which still live in the region's caves today.
It's not clear which species the newfound human hairs are from, since the human fossil record for this time span is exceedingly limited, the researchers say.
But the hairs' age "covers just before when we think modern humans emerged, and overlaps with the existence and end of Homo heidelbergensis," said study co-author Lucinda Backwell, a paleoanthropologist at the University of the Witwatersrand in Johannesburg, South Africa.
"The hairs could belong to either of them, or of course to [a species] not yet recognized," added Backwell, whose findings appeared online January 31 in the Journal of Archaeological Science.
Not King of the Hill
Backwell and her colleagues used tweezers to extract 40 fossilized hairs resembling glass needles from one of the hyena coprolites.
Scanning-electron-microscope images revealed wavy bands of scales on the hairs—a pattern typical of modern primates, with human hair being the closest match.
(Related photos: "Best Microscopic Images of 2008 Announced" [October 15, 2008].)
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