The journal Science has reported the discovery of a set of human skull fragment fossils which do not appear to belong to any known human species. According to preliminary analysis, these fossils might imply the existence of an unknown human ancestor species. The skull fragment fossils were discovered by Chinese paleontologists over a six-year period in the rural town of Xuchang in China’s central Henan province and are believed to be around 105,000 to 125,000 years old.
The researchers have identified physiological similarities between both Neanderthals and several early human species. While the back of the skulls and ear canals resemble Neanderthal skulls, these fossils show a much flatter brow and thinner bone density similar to early human species. However, the particular mix of features found in the skulls is unlike any other known species and might, therefore, represent a completely new human ancestor species.
The team behind this announcement have dubbed the species “archaic Homo” and believe these fossils could fill in some of the gaps in our knowledge of “Old World” human species:
The Xuchang crania therefore provide an important window into the biology and population history of early Late Pleistocene eastern Eurasian people. As such, they are a critical piece in our understanding of the human evolutionary background to the subsequent establishment of modern human biology across the Old World.
Researchers have extracted DNA from the fossils in an attempt to classify their owners but have not yet completed their genomic analysis. Similar DNA analysis of other recently unearthed fossils has revealed the possible existence of Denisovans, another human ancestor which roamed the Earth around the same time as Neanderthals. However, little fossil evidence has been gathered on the Denisovans other than a handful of teeth, so linking these two species is difficult. Nonetheless, this new find and many recent discoveries about our early ancestors are beginning to show that the genetic lines between Neanderthals and humans might not be as neat as we thought. Could this be evidence of the long-sought "missing link?"