Analyses on an ancient human skull renews evolutionary relationships between Homo species.
Where did we come from? This is a longstanding question that we have been asking for generations. Though there is mounting evidence that several human lineages co-existed with Homo sapiens during the Middle and Late Pleistocene (about 130,000 years ago), the relationships between them remain debatable.
In the Geoscience Museum in Hebei GEO University sits a near-perfect preserved ancient human fossil known as the Harbin cranium. Belonging to what scientists are now calling a new human species named Homo longi or “Dragon Man,” the cranium is known to be the largest of Homo skulls so far. Published across three papers in The Innovation, the findings suggest that the Homo longi lineage may be our closest relatives, potentially reshaping our understanding of human evolution.
“The Harbin fossil is one of the most complete human cranial fossils in the world,” said author Qiang Ji, a professor of palaeontology of Hebei GEO university. “This fossil preserved many morphological details that are critical for understanding the evolution of the Homo genus and the origin of Homo sapiens.”
Discovered in the depths of Harbin City of the Heilongjiang province of China in the 1930s, the enormous skull is said to hold a brain as large as the modern human’s but had larger, almost square eye sockets, thick brow ridges, a wide mouth, and oversized teeth.
“While it shows typical archaic human features, the Harbin cranium presents a mosaic combination of primitive and derived characteristics setting itself apart from all the other previously-named Homo species,” said Ji, leading to its new species designation of Homo longi.
Utilising a series of geochemical analyses, Ji, Ni, and colleagues dated the Harbin fossil to at least 146,000 years ago, placing it in the Middle Pleistocene, a dynamic era of human species migration. During this period, it is hypothesised that the two lineages H. longi and H. sapiens could have encountered each other.
In studying the ectocranial sutures, scientists deduce that the skull likely belongs to a male individual of about 50 years old, living in a forested floodplain environment as part of a small community. Like Homo sapiens, the Dragon Man fed off the land, hunting animals and gathering fruits. Given the fossil’s large size as well as where it was found, the scientists suggest that the H. longi may have been well-adapted for harsh environments, thereby allowing them to migrate across Asia.
Further analyses pin the Homo longi as a closer relative to modern humans than Neanderthals. “It is widely believed that the Neanderthal belongs to an extinct lineage that is the closest relative of our own species. However, our discovery suggests that the new lineage we identified that includes Homo longi is the actual sister group of H. sapiens,” said Ni.
The scientists believe that these findings from the Harbin cranium present us with more evidence to understand the evolutionary relationships between the diverse Homo species and with it, we may rewrite our current understanding of human evolutionary history. [APBN]
Source: Ni et al. (2021). Massive cranium from Harbin in northeastern China establishes a new Middle Pleistocene human lineage. The Innovation.