Anthropologists working in Ethiopia say they've found the earliest direct evidence of a stone tool "kitchen," dating back 2.6 million years.

The stone tools were found in the same site as animal bones, which the researchers said indicate the use of tools by early human to feed themselves.

Michael Rogers, an assistant professor of anthropology at Southern Connecticut State University, was working in Gona, Ethiopia, when he found some small tools made from chipped stone.

Further excavation at the site revealed the tools and bones together.

"Our ancestors were using the artifacts to process animal parts, which probably shows that humans were expanding their diets to include animals and were no longer largely vegetarians," said Rogers, in a news release.

The area in Gona, known for its ancient stone tools, is near Hadar, Ethiopia, which the hominid fossil "Lucy" was found in 1974.

Researchers have found bones marked with stone tools in the Gona region before, Rogers said, but never in a controlled setting.

Rogers said he was surprised by the condition of the site, considering its age, and by the diversity in the stones found.

"Our ancestors had to know what kind of rock flakes the best," he said. "They were being very selective."