An international team of paleontologists, including the Spanish María Martinón-Torres and José María Bermúdez de Castro, have just described in 'Journal of Human Evolution' an ancient fossil skull, found in China and that does not resemble that of any other known hominid. . In fact, its features do not coincide with those of the human lineage that, when separated, gave rise to the Neanderthals, but it is not similar to the Denisovans, nor to our own species, which seems to indicate that the family tree of humanity hid another branch, still unknown. So far, several jaw, skull and leg bones have been recovered from this still unclassified hominin, labeled HLD 6, discovered in 2019 in a cave in Hualongdong, eastern China, and which belonged to a mysterious male individual. (a teenager between 12 and 13 years old) about 300,000 years old. In recent years, experts at the Chinese Academy of Sciences have tried hard to match the remains to a known lineage. But all their efforts have been in vain. The face of the puzzling hominin, for example, has a structure similar to that of modern humans, who separated from Homo erectus 750,000 years ago. But the lack of a chin and the remains of the limbs are much more reminiscent of a Denisovan, an Asian species that separated from Neanderthals more than 400,000 years ago. The fossil, therefore, displays a unique mosaic of ancient and modern features. A new human lineage? To unravel the mystery of HLD 6, about which several studies have already been published, scientists from the Chinese Academy of Sciences have worked this time together with the British University of York and the National Research Center on Human Evolution, in Burgos. And together, researchers believe they have discovered a completely new human lineage: a hybrid between the branch that led to modern humans (us) and the one that gave rise to other ancient hominins in the region, such as the Denisovans. Related News standard No A new fossil rewrites the history of our ancestors: hominids originated in Europe, not Africa ABC Science This is the theory supported by an international team after analyzing the remains of a fossil ape from a site of 8, 7 million years old In their work, the researchers took dozens of measurements of the jaw of HLD 6 and compared them to 83 other known fossil hominids using a technique called geometric morphometry, which uses statistics to compare the three-dimensional shapes generated by the measurements. . The skull and jaw of HLD 6 Wu et al., Journal of Human Evolution, 2023 The results indicate that HLD 6 has modern human-like features in its facial bones, but its lower jaw shows a more complicated set of features, mixing of ancient and modern, and lacks a chin, one of the distinguishing characteristics of modern humans. This mix of traits, therefore, means that the Hualongdong individuals could be related to Homo sapiens, Neanderthals or Denisovans, but also that they could belong to another lineage entirely. Difficult interpretation This is not the first time that a Pleistocene human fossil found in China does not fit easily into a specific lineage. Therefore, these 'different' remains tend to be explained as 'intermediate variations' on the path leading to modern humanity, whether an archaic example of Homo sapiens or a highly advanced form of Homo erectus. But many call this interpretation linear and simplistic and do not accept it as valid. And the truth is that more and more evidence is accumulating that points to a more complex reality. For example, genetic studies carried out on Neanderthal DNA in both Europe and Asia found evidence of a 'fourth lineage' of hominins that lived in the second half of the Pleistocene. But no one has yet found a single fossil that allows us to identify this mysterious group. Could HLD 6 be the missing fossil evidence to complete the puzzle? Of course, the results of this study further complicate, if possible, the already tortuous path that leads to modern humans. In fact, the authors consider that the authentic mosaic of physical characteristics of HLD 6 supports the coexistence of three different human lineages in Asia: that of Homo erectus, that of the Denisovans and this new lineage that is 'phylogenetically close' to us. MORE INFORMATION news No India releases the first images of the south pole of the Moon news No Hundreds of mummified bees are found in Portugal 3,000 years ago The first known remains of Homo sapiens in China date back to about 120,000 years ago, that is, they are much older modern than those of HLD 6. But the presence of this mysterious hominin seems to suggest that some of our 'modern characteristics' already existed in that region a long time before. It may even be that the last common ancestor between Homo sapiens and Neanderthals arose in southwest Asia and then spread to all continents. A theory that, of course, must be confirmed with more research and more findings like this.
