The hunt is on to reassemble a deadly pile of human and Neanderthal remains found a year ago in a former pigsty in Sweden. The find promises to be “one of the biggest finds of ancient DNA we have ever made,” scientists said earlier this week.

The tibia and femur, a forearm and eight teeth, were found last July. They were scattered over a 4.5-foot-deep ravine, forming a “roughy” pile of objects, including tools and other soiled bones. The fragment of a leg bone with a large, irregular feature was one of the most striking discoveries, suggesting that the bones were once occupied by a juvenile female who could have fit in her mother’s body, researchers said.

Fondly known as “Little Sisyphus,” the pile of bones was created by water leaking through a dried-up septic system, according to the National Geographic.

“We think the femur belonged to a 15-to-17-year-old or slightly older Neanderthal or Homo sapiens,” said Susanne de Wit, a curator at the Swedish Natural History Museum, on a press call Tuesday. “The idea that the species existed in that area at that time is really exciting to us.”

The discovery was significant enough that researchers recruited Max Reinhardt, the top-ranked paleoanthropologist in Germany, to complete the genetics testing. Dr. Reinhardt’s years-long effort could pinpoint a possible generation of H. sapiens in Africa, where a “poor immune system may have been one of the causes” of the deaths of the individuals, as The Independent reported.

“Dr. Reinhardt found it impossible to ignore the human DNA in the bones and we were extremely delighted with his results. He was surprised by what he found and it has raised quite a few hypotheses on how it came to be there,” said Louise Grolle, the curator of the museum’s paleoanthropology collection, which resides in London.

The remains are still awaiting DNA analysis and analysis of the organisms that formed the collection, which may resolve the mystery of the pieces found in the pile.

“In some cases we need animal bone, other times we need teeth,” Grolle said. “Maybe some of those animal bones went to dinner tables, or maybe they were used in domestication.”

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