The pit contained three sets of human bones, as well as animal skeletons and broken pottery. Workers at a private company found the pit in 2013, during the construction of a highway near the town of Osijek in eastern Croatia.
The skulls were intact. Two of them were also misshapen.
“A friend, the owner of this company, he called and told me, ‘Oh Mario, I think we have an alien here,'” recalled Mario Novak, an archaeologist at the Institute for Anthropological Research in Croatia. “Of course, it was a joke.”