A new Neandertal skeleton suggests these ancient humans had an extended period of brain growth compared to modern humans.

The beetling brows and forward thrusting faces of the classical Neandertal may have evolved before other characteristic features of their skulls, according to a new report.

Researchers have revealed new details about the brain, pelvis, hands, and feet of Australopithecus sediba, a primitive hominin that existed around the same time early Homo species first began to appear on Earth. The new Au. sediba findings, unearthed in Malapa, South Africa, make it clear that this ancient relative displayed both primitive characteristics as well as more modern, human-like traits.

Due to the “mosaic” nature of the hominin’s features, researchers are now suggesting that Au. sediba is the best candidate for an ancestor to the Homo genus.

Two partial skeletons unearthed from a cave in South Africa belong to a previously unclassified species of hominid that is shedding new light on the evolution of our own species, Homo sapiens, researchers say. The newly documented species, called Australopithecus sediba, was an upright walker that shared many physical traits with the earliest known Homo species—and its introduction into the fossil record might answer some key questions about what it means to be human.