Xiongnu
In the 1920s, Pyotr Kozlov's excavations of the royal tombs at the Noin-Ula burial site in northern Mongolia that date to around the first century CE provided a glimpse into the lost world of the Xiongnu. Other archaeological sites have been unearthed in Inner Mongolia and elsewhere; they represent the Neolithic and historical periods of the Xiongnu's history. Those included the Ordos culture, many of them had been identified as the Xiongnu cultures. The region was occupied predominantly by peoples showing Mongoloid features, known from their skeletal remains and artifacts. Portraits found in the Noin-Ula excavations demonstrate other cultural evidences and influences, showing that Chinese and Xiongnu art have influenced each other mutually. Some of these embroidered portraits in the Noin-Ula kurgans also depict the Xiongnu with long braided hair with wide ribbons, which is seen to be identical with the Ashina clan hair-style. Well-preserved bodies in Xiongnu and pre-Xiongnu tombs in the Mongolian Republic and southern Siberia show both Mongoloid and Caucasian features. Analysis of skeletal remains from sites attributed to the Xiongnu provides an identification of dolichocephalic Mongoloid, ethnically distinct from neighboring populations in present-day Mongolia. Russian and Chinese anthropological and craniofacial studies show that the Xiongnu were physically very heterogenous, with six different population clusters showing different degrees of Mongoloid and Caucasoid physical traits. These clusters point to significant cross-regional migrations (both east to west and west to east) that likely started in the Neolithic period and continued to the medieval Mongolian period.
Noin-Ula burial site
Despite the aforementioned excavated Noin-Ula portrait indicating Mongoloid lineage of the Xiongnu, Euro-centric observers of Xiongnu culture and history try to place the Xiongnu people in a non-Mongoloid or non-Asian ancestry or descendancy. Among the most important artifacts from Noin-Ula are embroidered portrait images. These shed light on the ethnicity of the Xiongnu, albeit controversially. It has been claimed that the portraits depict Greco-Bactrians, or are Greek depictions of Scythian soldiers from the Black Sea. Such suggestions are far-fetched. There are several historical sources confirming the appearance of the Xiongnu. In 350 AD, for example, power in the South Xiongnu state of Chjao (Pin. "Zhao") was seized by a usurper, a Chinese named Shi Min, who ordered all the Xiongnu in the state exterminated; in the slaughter "many Chinese with prominent noses" died, suggesting the Xiongnu had "prominent noses" compared to those of the Chinese. In the famous Chinese bas-relief "Fight on the bridge" the mounted Xiongnu are shown with big noses. A skull analysis of Xiongnu burials made by G.F. Debets found a distinct Paleo-Siberian type of Asian facial appearance with "not a flat, but with not strongly protruding nose", somewhat similar to some North American Indians. This type is represented on the embroidery from Noin-Ula. What to the rest of the Chinese looked like a high nose, to the Europeans looked like a flat nose.