It turns out that our ancient ancestors may have been food for hyenas and other carnivores about 500,000 years ago. The new discovery may shed some light on the food chain that existed in the past.

Early humans are believed to have competed for space and resources with large carnivores that probably occupied the same areas during the Middle Pleistocene. However, there is little evidence for direct interaction between humans and carnivores during this period of time.

In the new study, though, researchers may have actually found evidence of this interaction. In this case, the scientists studied the shaft of a femur from a skeleton of a 500,000-year-old hominin that was found in a Moroccan cave.

After examining the bone, the researchers found various fractures and tooth marks. This, in particular, showed that the bone had been chewed on by a carnivore. More specifically, the scientists found tooth pits, as well as scores and notches ,that were clustered at the two ends of the femur. In addition, the softer parts of the bone had been completely crushed. The marks themselves were covered with sediment, which suggests that the marks are extremely old.

It's likely that the marks themselves were made by hyenas shortly after the hominin's death. However, researchers aren't sure whether the bone had been eaten as a result of predation or had been scavenged soon after death. With that said, this is the first evidence that shows that humans were a resource for carnivores during the Middle Pleistocene, whether it was after humans had died or while they were still alive.

"Although encounters and confrontations between archaic humans and large predators of this time period in North Africa must have been common, the discovery...is one of the few examples where hominin consumption by carnivores is proven," said Camille Daujeard from the Museum National D'Histoire Nautrelle in France, one of the researchers involved in the latest study.

It's likely that humans at the time could have acted as both hunters and scavengers. However, it's also possible that early humans themselves were targeted as carrion or even as prey by larger predators.

The findings were published in the April 27 issue of the journal PLOS ONE.