Abstract: Genomic analysis of ancient wild animal remains not only holds significant importance for the conservation and utilization of genetic resources of wild animal species, but also helps us understand the diet compositions and hunting activities of ancient human beings and their social-economic development patterns. Ancient DNA technology has been widely used in archaeological research. Among its many strengthens, it’s potential in deciphering the genetic information carried by biological samples at the molecular level has been well-recognized, and many researchers have conducted ancient DNA analysis to distinguish domestic animals and wild animals. Apart from that, when combined with historical and archaeological evidence, it provides us with strong scientific and technological support so that we can get the full picture of ancient human societies, including its origins and the evolutionary process they went through. In this study, the ancient DNA of nine animal samples excavated from Changning, Mogou, Quanhucun and Dashigou sites in Northwest China and morphologically identified as “sheep” or “goats”, was studied using ancient DNA technology. Ancient DNA extraction, library construction, and high-throughput sequencing were carried out, and the mitochondrial genome sequences of the nine samples were successfully obtained. Alignment analysis between the genomic sequences of these samples and the 146 mitochondrial genomic sequences of Cervidae and Bovidae (used as the reference data) was performed. As shown by the results of alignment analysis, these nine samples were identified as belonging to four different wild animal species within the families of Cervidae and Bovidae: the Siberian roe deer (Capreolus pygargus) of the genus Capreolus within the subfamily Odocoileinae, and the Przewalski’s gazelle (Procapra przewalskii) and Tibetan gazelle (Procapra picticaudata) of the genus Procapra within the subfamily Antilopinae, as well as the Sumatran serow (Capricornis sumatraensis) of the genus Capricornis within the subfamily Caprinae. Two phylogenetic analyses were conducted on the mitochondrial genome data extracted from the Odocoileinae, Caprinae, and Antilopinae subfamilies. Bayesian phylogenetic tree and Maximum Likelihood phylogenetic tree were constructed. It was shown that each of the nine samples clustered with the corresponding species identified by the alignment analysis, which was consistent with the results of principal component analysis on the same data set where the nine samples were assigned to the corresponding species identified in the alignment analysis. Genetic distance calculation between individuals based on ancient and modern samples showed that each of the nine samples is the closest genetically to the specific species identified. All of the above results highlight that ancient DNA technology can overcome the shortcomings of morphological approaches in species identification of ancient animals. Considering other wild animal bone remains excavated from the four sites, it can be concluded that the ancient people in pre-historic northwest China used wild animals as a supplement to domestic animal resources for food, sacrificial offering and bone tool manufacture. This study holds great significance in that it, at the molecular level, provided new evidence for and corroborated the findings of previous archaeological research on animals living in pre-historic times.

Key words: Ancient DNA, Species identification, Northwest China, Prehistory, Wild animal resources