A team of paleoanthropologists, led by Christopher J. Bae from the University of Hawai‘i at Mānoa and Xiujie Wu from the Insтιтute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, has introduced Homo juluensis, a newly identified hominin species. This species, whose name translates to “big head,” thrived in eastern Asia between 300,000 and 50,000 years ago, marking a significant addition to the Late Quaternary human lineage.

Primary hominin species from eastern Asia during the Late Quaternary (~300,000–50,000 years BP). Credit: Bae, C.J., Wu, X., Nat Commun (2024)

The introduction of Homo juluensis builds on decades of research into Asia’s hominin fossil record. The findings provide a clearer understanding of the diversity and complexity of ancient human species that coexisted during the Middle and Late Pleistocene epochs.

Homo juluensis is defined by a mix of features found in fossils from sites such as Xujiayao and Xuchang in northern and central China. The fossils include large crania with thick skulls, traits reminiscent of Neanderthals, as well as characteristics shared with modern humans and Denisovans. The species is thought to have been skilled in making stone tools, processing animal hides, and hunting wild horses, which likely contributed to their survival in challenging environments.

For years, paleoanthropologists have grappled with the so-called “muddle in the Middle,” a term describing the confusion surrounding the classification of Middle Pleistocene hominin fossils. Many specimens were grouped into broad categories like “archaic Homo sapiens” or “Middle Pleistocene Homo.” However, Bae and Wu’s work proposes a more nuanced taxonomy, suggesting that eastern Asia hosted at least four distinct hominin species: Homo floresiensis, Homo luzonensis, Homo longi, and the newly named Homo juluensis.

A facial approximation of Homo floresiensis. Credit: Cicero Moraes, CC BY-SA 4.0

In a May 2024 study, Bae and Wu argued that fossils previously categorized as belonging to Denisovans, including remains from Tibet, Taiwan, and Laos, could also belong to Homo juluensis. This hypothesis is based on similarities in jaw and teeth structures among fossils from these regions.

The research team emphasized that naming Homo juluensis is not merely about taxonomy but about improving science communication. “This study clarifies a hominin fossil record that has tended to include anything that cannot easily be ᴀssigned to Homo erectus, Homo neanderthalensis, or Homo sapiens,” Bae explained in a press release. “Ultimately, this should help with science communication.”

In a commentary in Nature Communications, Bae and Wu highlighted the importance of new terminology for understanding evolutionary models. “Thanks largely to a growing hominin fossil record, the field of Late Quaternary eastern Asian paleoanthropology is contributing tremendously to how we view and refine these models,” they wrote.

Homo juluensis challenges unilineal evolutionary models. According to the researchers, the eastern Asian fossil record underscores the need to revise traditional interpretations of human evolution to reflect the diversity and hybridization events revealed by recent findings. The discovery of Homo juluensis marks a significant step forward in unraveling the intricate web of human ancestry.

More information: Bae, C.J., Wu, X. (2024). Making sense of eastern Asian Late Quaternary hominin variability. Nat Commun 15, 9479. doi:10.1038/s41467-024-53918-7