"These bone tools have shaping and use marks that indicate they were used for scraping hides to make leather and for scraping pelts to make fur," says Emily Hallett of the 'Lise Meitner' Pan-African Evolution research group at the Max Planck Institute for the Science of Human History in Germany. "At the same time, I found a pattern of cut marks on the carnivore bones from Contrebandiers Cave that suggested that humans were not processing carnivores for meat but were instead skinning them for their fur."

Clothing made of fur and hides likely played an important role in the ability of early humans to move into colder parts of the world during the Pleistocene. "Genetic studies of clothing lice by other researchers have suggested that clothing originated in modern humans at least 170,000 years ago in Africa," says Hallett. But not much is known about the tradition of clothing and its manufacture because fur and other organic materials generally aren't preserved in the archaeological record, especially not in deposits 100,000 or more years old. The new findings provide "highly suggestive proxy evidence for the earliest clothing in the archaeological record," the authors write.

The researchers, including the late Harold Dibble, an influential archaeologist from the University of Pennsylvania, identified 62 bone tools from the Contrebandiers Cave in all. The bones were sculpted in diverse ways to create regular shapes. They were also polished and smoothed. Alongside the bone tools were the remains of sand foxes, golden jackals, and wildcats, all with marks consistent with the notion that people had removed their skins for furs utilizing techniques that still are used today. The remains of other kinds of animals related to modern cattle found within the cave show different markings, suggesting they were processed instead for meat.

In addition, researchers found a cetacean tooth tip, which they report bears what is likely a combination of human and non-human modifications, This makes it the earliest documented use of a marine mammal tooth by humans and the only verified marine mammal of this age from North Africa.

Overall, the evidence from Contrebandiers Cave highlights the pan-African emergence of complex culture, including the use of multiple and diverse materials for specialized tool manufacture. "Our findings show that early humans were manufacturing bone tools that were used to prepare skins and furs, and that this behavior is likely part of a larger tradition with earlier examples that have not yet been found," Hallett says.

Hallett says she's curious to see whether other archaeologists will find comparable carnivore skinning patterns in other assemblages of bone. She also wants to experimentally manufacture and use bone tools in a controlled environment to understand the time and labor investment that went into making and maintaining these early bone tools.

This work was supported by the National Science Foundation, the University of Salamanca, the Institute of Human Origins, a John Templeton Foundation grant to the Institute of Human Origins at Arizona State University, the School of Human Evolution and Social Change, the Australian Research Council, the Leakey Foundation, the National Geographic Society, and the University Research Foundation of the University of Pennsylvania. Harold Dibble passed away on June 10, 2018 and is missed by his team.