A “provocative” new piece Nature has proposed a whole new group of ancient humans – cousins of the Denisovans and Neanderthals – who once lived side by side Homo sapiens in East Asia more than 100,000 years ago.
The brains of these extinct humans, who probably hunted horses in small groups, were much larger than any other hominids of their time, including our own species.
Paleoanthropologist Xiujie Wu of the Chinese Academy of Sciences (CAS) and anthropologist Christopher Bae of the University of Hawaii have named this new group the Juluren, which means “people with a big head.”
In the past, some scientists have used the Juluren (Homo juluensis) fossils to Denisovans (pronounced duh-nee-suh-vns), a group of ancient humans, related to Neanderthals, who once lived alongside modern humans and even mated in parts of Asia.
But Wu and Bae took a closer look and say the characteristics of some fossils found in China cannot easily be attributed to modern humans, Neanderthals, Denisovans or Homo erectus, the hominids that came before our own kind.
Their mosaic of traits suggests a mix of ancestry between different hominin groups, all of which lived in the same regions of Asia between 300,000 and 50,000 years ago.
“Collectively, these fossils represent a new form of large-brained hominin,” Wu and Bae concluded in the journal PaleoAnthropology earlier this year.
Fossils from Xujiayao. (Wu, 2024)
“Although we started this project several years ago, we did not expect that we would be able to propose a new species of hominin (human ancestor) and then classify the hominin fossils from Asia into different groups,” says Bae.
Anthropologist John Hawks, who was not involved in the research, calls Bae and Wu's recent comments “provocative,” and in his blog earlier this year he reviewed their research and agreed that while the evidence from the Juluren is limited , the human record in Asia 'more extensive than most specialists have assumed.”
Until recently, all hominin fossils found in China were mismatched Homo erectus or Homo sapiens were lumped together. Compared to hominid fossils in Africa and Europe, the human fossil record in East Asia is poorly differentiated and described.
“Giving all these groups the same name only makes sense as a contrast to recent humans, not as a description of their populations in space and time,” Hawks writes on his blog.
“I don't see the name Juluren as a replacement for Denisovan, but as a way to refer to a particular group of fossils and their possible place in the network of ancient groups.”
Examples of fossils that fit this Homo juluensis (blue five-pointed stars), including Xujiayao, Xuchang, Xiahe, Penghu, Denisova and Tam Ngu Hao 2. (Bae & Wu, Nature communication2024)
In the past twenty years alone, the human family tree has gone from a carefully pruned bonsai to a bushy, tangled mess, and picking apart and naming all the different branches is proving quite a challenge.
It seems like every few years new lines emerge, intertwining with other branches of life before inexplicably coming to an end.
In 2003, scientists discovered Homo floresiensis – the smallest known human species that lived on an island in Indonesia at least 100,000 years ago.
In 2007, archaeologists discovered Homo luzonensis – a completely new hominid species from 67,000 years ago – in the Philippines.
In 2010, DNA analysis revealed the existence of ancient Denisovans in what is now Russia, near the border of Kazakhstan and Mongolia.
In 2018, paleoanthropologists obtained a fossil from northeastern China that turned out to be an extinct species of archaic human, possibly related to the Denisovans. It wasn't until 2021 that scientists formally designated the species as Homo lungi.
Now Wu and Bae want to propose Homo juluensis to the revolution.
The different fossils that belong to it H. juluensis emerge from the face and jaw, and apparently exhibit classic Neanderthal-like dental features. But some traits are not seen in other known hominins, including the Denisovans.
'That is becoming increasingly clear [in] the East Asian hominid fossils… a greater degree of morphological variation is present than originally thought or expected,” write Wu and Bae.
For example, in 2023, scientists found a hominid fossil in Hualongdong, China, unlike any other human fossil ever recorded. He's not Denisovan or Neanderthal, and he doesn't fit in well H. juluensis or H. langi.
Wu and Bae say this is a good example “of the complexity of human evolutionary history.”
“In any case,” they write, “the East Asian record pushes us to recognize how complex human evolution is in general and actually forces us to reconsider and reconsider our interpretations of various evolutionary models in order to to better match the growing fossil record.”
The commentary was published in Nature communication.
