Ancient ape fossils discovered in Germany are giving new clues to the origins of human bipedalism, Nature reports. The remains, dated to 11.6 million years ago, include arm, shin, and thigh bones from four individuals—as well as vertebrae and ankle bones that suggest the ape, named Danuvius guggenmosi, could have walked upright. If true, this would be some of the earliest evidence of bipedalism among human ancestors, who are thought to have split from the branch that includes bonobos and chimpanzees some 7 million years ago, the researchers report this week in Nature. Prior to this find, the earliest hints of bipedalism are in fossils 6 million to 7 million years old. But not everyone is convinced—and researchers still need to figure out where D. guggenmosi belongs in the primate family tree.