Rare remains uncovered in China over the past year may finally throw a wrench into one of the great mysteries of science.
Thousands of footprints belonging to a certain type of animal — but in theory thought to have been created by an animal, rather than by man — have been found by archaeologists in Linxia, in central China. Encompassing 27 different prints on the Chinese-Tibetan border, the mysterious animal prints have captured the attention of the scientific community for more than a century. They were once considered the result of a tragic accident, but now scientists think they may have been created by a different animal altogether: an unknown human ancestor.
The extraordinary prints — each measuring two feet and squared, with prints specifically and unmistakably made by feet — were discovered in 1930, in the Heilongjiang section of Linxia. But for decades they proved to be an elusive puzzle, and for years scientists claimed they were made by a bear. In 1982, a search of the area revealed evidence of the original shoe — a common tusked animal — but in 2002, several odd patches of time had leaked through the perfect pattern.
The mystery of the Linxia prints became a hot topic in the journal Nature after researchers identified the footprints in 2013. As Time noted, in the article, the paper was co-authored by new Caltech researcher Stephen W. Brusatte, and now their findings have received even more attention — with no one quite sure whether they belong to an animal or a human ancestor.
Brusatte first drew the eye of researchers when he wrote in Nature that he thought the prints must belong to Homo erectus, a hominid that lived in Asia at least 2.5 million years ago, and previous research had suggested the prints were made by H. erectus. But there was more. Brusatte’s initial review of the prints showed a distinct “chunk in the middle” of the prints, and to the researcher’s surprise, the two largest-sized prints in that area were not made by H. erectus. Instead, as he explained in the Nature article, “I proposed that these marks in the middle were placed by a bear.”
This was a result that startled some scientists, but it apparently wasn’t the least bit surprising to others. On the same day, Brusatte teamed up with researcher Elisabeth Dytham, a researcher from Scotland who also spoke to the BBC, to offer a new study that pegged the topmost image of the prints as a human foot. According to Dytham, she had argued the highest image was a foot in a previous paper.
“It was just a really interesting puzzle and we only started following it because we were quite flummoxed,” Dytham said in an interview with The Telegraph. “It became very clear in our brain, and I think Stephen was very open-minded and so was me.”
This has left all manner of questions open for researchers. For one, how can the footprints be so distinctive, in the ways they are? Also, while a different animal than the bear makes the prints, the presence of a footprint-shaped area created by the shape of the animal to which it belonged suggests the type of animal that made them.
As Curtatte explained to Science Alert, scientists do not yet know for sure what was the subject of the prints. But from the looks of it, it could very well be that it was another animal — or it could have been an other-worldly creature, created entirely by man. As Brusatte said, “There are all sorts of interpretations and possibilities,” and yet to this day, the Linxia prints remain a mystery.