As the modern human origins debate continues to evolve, eastern Asia (including both East and Southeast Asia) is playing an increasingly important role. It is now evident that there were multiple dispersals out of Africa and across Eurasia beginning well before 60,000 years ago (ka)¹. Questions remain, however, regarding the dispersal routes (and timing thereof) that modern humans took out of Africa. Currently, it appears that initial late Middle Pleistocene (<300 ka) human movements out of Africa spread into the Levant² and touched southeastern Europe³ before spreading more widely across southern Asia, eventually arriving in Southeast Asia, including southern China, sometime between 120 ka and 60 ka^4,5. The early spread across northern Asia has been less clear. Most data suggest that the northern Asian expansion of modern humans largely occurred after 60 ka, with sites appearing in Siberia, Mongolia, northern China, Korea and Japan soon after 50 ka^5,6 (Fig. 1). This later northern expansion included a westward dispersal into Europe. Writing in Nature Ecology & Evolution, Yang et al.⁷ report on multidisciplinary research from the northern Chinese site of Shiyu that brings some clarity to the nature of the dispersal of modern humans across Northeast Asia⁷.

The potential importance of Shiyu has been evident since its discovery in 1963, as it has yielded more than 15,000 stone tools, including blades, Levallois flakes, other artefacts (for example, a perforated black disc and a bone tool) and thousands of vertebrate remains, including at least one human fossil⁸. Although the site has been traditionally considered one of the most important sites in northern China, particularly as part of the ‘small tool tradition’ model⁸, the multidisciplinary re-examination of the site and materials by Yang et al.⁷ reveals the full importance of Shiyu. The authors used a multi-pronged geochronological approach (using accelerator mass spectrometry radiocarbon and optically stimulated luminescence dating) to reveal that the earliest cultural deposits at Shiyu date to ~45 ka, several thousand years older than the oldest cultural deposits at the Shuidonggou site, located a few hundred kilometres to the west. As a result of this new dating reconstruction, Shiyu becomes the oldest site of the Initial Upper Palaeolithic (IUP) in the region and contemporaneous with IUP sites in Europe. It should be noted that older deposits are present in Shuidonggou, but these older stratigraphic levels currently lack cultural materials⁹.

Having established their age, what is the nature of the archaeology at Shiyu? In addition to elements characteristic of IUP technology, such as blade tools, the generally minute size of the stone artefacts might be considered representative of a higher level of technological sophistication. However, the presence of small core-flake products at Shiyu may actually reflect the size of the stone nodules that are locally available. For instance, Lin and colleagues¹⁰ recently showed that miniaturized stone tools were regularly produced at the Fanjiagouwan locality in Salawusu, northern China, but were considered to be related primarily to only small stone nodule sources being available some 40 km away. Because Fanjiagouwan dates to between 100 and 90 ka, Lin and colleagues¹⁰ could only conservatively conclude that the lithics were left there by modern humans, Denisovans and/or Neanderthals.

The generally local nature of the Shiyu stone tools makes an interesting contrast with the presence of obsidian artefacts that were geochemically fingerprinted to locations some 800 and 1,000 km away in Northeast China and the Russian Far East (Changbai and Gladkaya). As Yang et al.⁷ suggest, this is quite an early age (~45 ka) for long-distance movement of a raw material source like obsidian, and it could represent long-distance movement of these foragers or some trade interaction sphere. Earlier, Norton and Jin¹¹ had raised these possibilities as well using the presence of shell in Zhoukoudian Upper Cave that appear to have originated from the coast, which would have been some 400 to 600 km away at the time of occupation. Early movement of obsidian in different regions of the Japanese archipelago is also comparably dated to Zhoukoudian Upper Cave^5,11. Given that Zhoukoudian Upper Cave is younger (~35 to ~33 ka¹²), it is clear that long-distance transport of materials in the region can be easily pushed back ~10,000 years with the new results from Shiyu.

It is unfortunate that the only human fossil identified from Shiyu has been lost, as a great deal of potential information could have probably been obtained from additional analysis of it — not least a clearer idea of what species made the artefacts at the site. Elsewhere in eastern Asia, morphological and genetic study of fossils from sites like Zhoukoudian Upper Cave, Tianyuandong and Ryonggok Cave have given more clarity to the regional middle Late Pleistocene human evolutionary record. It might be worthwhile to explore a proteomic study using zooarchaeology by mass spectrometry (ZooMs) on the thousands of vertebrate remains from Shiyu to see whether other human fossils can be identified.

Future research must also evaluate the utility of using models developed for the European record and simply applying them to the East Asian record rather than developing in situ models. Asian specialists have raised serious questions (for example, refs. ^4,5,13,14) about this practice over the past several decades, and interest in this is increasing as palaeoanthropology and Palaeolithic archaeology undergo decolonization¹⁵. It would be useful to see whether the Shiyu material fits into a two-stage (Early and Late) Palaeolithic sequence, as proposed by Gao and Norton¹³, or whether something else is happening. The presence of Levallois flakes (normally representing the Middle Palaeolithic) in the same stratum as blades (normally representing the Upper Palaeolithic) suggests an absence of a clear earlier Middle Palaeolithic at the Shiyu site. Regardless, it may be time for researchers in eastern Asia to re-examine their own materials without having to rely on behavioural models created for other regions of the world.

Shiyu has always been a site with a great deal of potential. The latest multidisciplinary study⁷ of the site and materials contributes tremendously to furthering our understanding of the complexity of the Late Palaeolithic in Northeast Asia. More detailed multidisciplinary examinations of similar sites in the region are likely to provide further surprises.