May 6, 2024

Chinless 300,000-year-old skull could belong to a new, yet unidentified human lineage

A bizarrely shaped ancient skull discovered in China might trigger a revision of the story of human advancement. Unlike any hominin discovered before, this fossil does not nicely suit the established evolutionary paths of Neanderthals, Denisovans, or contemporary human beings. At a loss regarding which branch of the human ancestral tree to place the specimen onto, the scientists have instead proposed the fossil may come from a totally new branch.

The fossils belong to a 12 or 13-year-old. Credit: Procedures of the National Academy of Sciences.

An enigmatic human: could this be a new hybrid family tree?

Generally, Pleistocene-era hominin fossils from China have been viewed as transitional phases on the path to Homo sapiens or as variations of Homo erectus. Yet, HLD 6 does not align with the Homo erectus types and instead displays traits similar to more current hominin family trees. It looks like HLD 6 is stuck in a limbo between the lineage that produced us contemporary people and other more primitive branches of the Homo genus.

Upon closer inspection, HLD 6 has actually proven to be a bit of an enigma due to its distinct physical features that diverged from recognized human lineages. It looks like HLD 6 is stuck in a limbo between the family tree that produced us modern-day human beings and other more primitive branches of the Homo genus.

The findings appeared in the Proceedings of the National Academy of Sciences.

According to the team, which included researchers from the Chinese Academy of Sciences, Xian Jiaotong University, and the University of York in the UK, these remains might possibly be a hybrid in between the branch resulting in contemporary humans and the one producing other ancient hominins in the exact same region, such as the Denisovans.

The fossils jawbone has a distinct triangular shape and bend, closely looking like both modern human beings and Late Pleistocene hominids. The lack of a chin is more reminiscent of the Denisovans, an ancient hominin group unique from Neanderthals and Homo sapiens.

The story of human advancement stays a work in development, with many surprises waiting to be discovered.

The virtually rebuilded HLD 6 skull. Credit: Wu Liu et al.. Procedures of the National Academy of Sciences ( 2019 ). DOI: 10.1073/ pnas.1902396116.

Back in 2019, Chinese researchers came across a partial skull, jawbone, and leg bones in Hualongdong, eastern China. The remains, which come from a juvenile approximated to have actually lived around 12 or 13 years, were dated to roughly 300,000 years back under the designation “HLD 6”.

Past genomic research study on Neanderthal remains has meant a 4th family tree of hominins during the Middle to Late Pleistocene, but there was no conclusive physical proof previously. This brand-new discovery might finally fill out an essential gap in our evolutionary history.

Human family tree. Credit: Nature.

Upon closer assessment, HLD 6 has actually shown to be a little bit of an enigma due to its distinct physical features that diverged from recognized human lineages. At first, it was thought that HLD 6s combined features might be associated to its young age. However, relative analyses with both adult and immature hominin specimens have unmasked this theory.

It is difficult to make definite claims based on a single specimen– and an insufficient one to boot– the researchers posit that Asia might have once hosted 3 existing together family trees: Homo erectus, Denisovan, and the freshly found hominid. This would indicate that specific “contemporary” characteristics emerged long before Homo sapiens existence in China about 120,000 years back.

A bizarrely shaped ancient skull unearthed in China might trigger a modification of the story of human development. Unlike any hominin found before, this fossil does not nicely fit into the recognized evolutionary courses of Neanderthals, Denisovans, or modern-day human beings. At a loss as to which branch of the human family tree to place the specimen onto, the researchers have rather proposed the fossil might belong to a completely new branch.