A skull discovered in northeast China in the 1930s has finally been accurately dated and studied by paleoanthropologists, revealing the presence of a previously unknown species of extinct human relatives in the Far East.
Homo longi, nicknamed the Dragon Man, had a large brain, even larger than the average brain mass of today’s people (1,400 cubic centimeters in volume compared to the currently common 1,200 cm³). On the other hand, the massive skull structure, the bulges in the eyebrow area (technically known as the supraorbital torus) and the huge teeth bring the creature closer to archaic members of our genus, such as the Neanderthals.
Details on the anatomy, dating, and classification of H. longi have just been published in three articles in The Innovation journal. The study’s authors include Xijun Ni from GEO Hebei University and the Chinese Academy of Sciences, and Chris Stringer from the UK, from the Natural History Museum in London.
The skull examined by the team is known to be found while building a bridge in Harbin City in 1933, but detailed information about the context of the discovery has since disappeared.
To better understand the origins of the fossil, Ni and colleagues used a number of techniques, taking into account the details of the chemical makeup of the soil and other fossils from the Harbin area. Fortunately, sediments from the same soil stuck in the nasal cavity of the skull, which allowed for a relatively reliable comparative analysis. In addition, based on the gradual conversion of the uranium atoms present in the material into other chemical elements (a so-called radioactive decay), a minimum age for bones could be estimated directly.
This sum of clues led the team to conclude that the minimum age of the Dragon Man is 146,000 years. In turn, data on sediments from the Harbin region suggest that the skull came from strata that are between 138,000 and 309,000 years old. It is, therefore, the time when human lineages such as Homo sapiens in Africa and Neanderthals in Europe appeared and spread.
Modern anatomy humans and Neanderthals, however, weren’t the only hominins (members of the group that includes our species and their closest relatives and ancestors) populating the Old World at the time.
There was also the puzzling group of Denisova people who lived in Siberia and are only known for fragments such as teeth and finger bones – but also for their DNA, which scientists have already “spelled out” to a large extent. It can be said that Denisovans are practically a “disembodied” genome, as we know almost nothing about their anatomy.
Almost nothing, except that they also had large molars, just like H. longi. Could the Dragon Man actually be a Denisovan?
“It’s hard to say whether they were closely related,” Ni mused in an interview with Folha. “Both have large molars, but that’s a primitive trait. [ou seja, a versão ‘original’] of the genus Homo, that is, it cannot be used to define this type of relationship. “
“If we take into account this detail and the close relationship between Harbin’s skull and Xiahe’s jaw in Tibet, it could certainly be a Denisova person who could also be associated with Denisova people,” adds Stringer. “But until we have a genome of the species from a relatively complete skull, we won’t be able to solve this problem properly.”
The team’s work also includes a comparative analysis of all fossils of the genus Homo, using their morphological features to group them according to their “genealogical” proximity between them. According to the analysis, the Chinese skull, along with other relatively little studied Asian hominins, would form the closest group to our species, followed by the Neanderthals.