The upper jawbone and partial cheek bone represent a mysterious unknown species that lived in present-day Spain between 1.1 million and 1.4 million years ago, according to a new study

The prehistoric facial bones were found buried in 50 feet of mud and silt, and are believed to be 1.1 to 1.4 million years old, researchers said.

The research team at the Atapuerca archaeological sites in Burgos, Spain, has just broken its own record by discovering, for the third time, the oldest human in Western Europe.