Pastoral subsistence and mounted fighting in the Eastern Tianshan Mountain region: New insights from the Shirenzigou worked bone assemblage

Abstract

Situated at a geographic crossroads, the eastern Tianshan Mountain region in northwest China is crucial to understanding various economic, social, and cultural developments on the Eurasian Steppes. One promising way to gain a better knowledge of ancient subsistence economy, craft production, and social change in the eastern Tianshan Mountain region is to study the artifact assemblages from archaeological contexts. Here, we present an analysis of 488 worked animal bones from the large site of Shirenzigou (ca. 1300-1 BCE), to date the largest assemblage of this kind uncovered in the eastern Tianshan Mountain region. We classified these worked bones into six categories, including "ritual objects", "ornaments", "tools", "worked astragali", "warfare and mobility", and "indeterminate". The identification of animal species and skeletal elements indicates that worked bones from Shirenzigou are characterized by a predominance of caprine products, particularly worked astragali, which is consistent with the large proportion of caprine fragments found in animal remains associated with food consumption. This demonstrates the contribution of caprine pastoralism to bone working activities at Shirenzigou. The making of most worked bones does not appear to have required advanced or specialized skills. Considering the absence of dedicated bone working space, alongside the variability in raw material selection and in dimensions of certain types of artifacts, we infer that worked bone production at Shirenzigou was not standardized. In terms of raw material selection and mode of production, Shirenzigou differed from their settled, farming counterparts in the Yellow River valley of northern China. In addition, along with the evidence for violence and horseback riding, the increasing use of bone artifacts associated with warfare and mobility during the late occupation phase of Shirenzigou reflects growing social instability and implies the likely emergence of single mounted horsemen, equipped with light armors, in the region during the late first millennium BCE. Our results provide new insights into animal resource exploitation and changing lifeways of early pastoral societies in the eastern Tianshan Mountain region, expanding our knowledge of the economic, social, and political milieu of late Bronze Age and early Iron Age eastern Eurasia.

Fig 1. Map showing the location of Shirenzigou in the eastern Tianshan Mountain region, northwest China.

Map produced in ArcMap 10.7.1. The digital elevation model was acquired from the Geospatial Data Cloud site, Computer Network Information Center, Chinese Academy of Sciences (http://www.gscloud.cn).

Fig 2. Photo showing modern natural landscape surrounding the site of Shirenzigou.

Fig 3. Calibrated radiocarbon dates for Shirenzigou.

Conventional radiocarbon ages were generated by the Accelerator Mass Spectrometry Dating Laboratory of Peking University in Beijing. Calibration was performed in OxCal v4.4 [53], using IntCal20 as the calibration curve [54] (https://c14.arch.ox.ac.uk/oxcal/OxCal.html). Most radiocarbon dates in this figure (IDs 1–8, 11–13) were reported in previous research [–57], and in this study we recalibrated these data using the most recent calibration curve (S1 Table).

Fig 4. Examples of oracle bones from Shirenzigou.

1) specimen from 2009HBSIIIT0822④; 2) specimen from 12XBSIIIT0720II-3④. The close-ups at the bottom show brownish burned marks on the scapulae (Left: specimen from 2009HBSIIIT0822④; Right: specimen from 2011XBSIIIHD12).

Fig 5. Examples of ornaments from Shirenzigou.

1) specimen from 12XBSIIIT0721I-3④; 2) specimen from 12XBSIIIT0721II-2JX6②; 3) specimen from 2010HBSⅢT0619Ⅲ②; 4) specimen from 2007BSDM016.

Fig 6. Examples of bone awls from Shirenzigou.

1) specimen from 12XBSIIIH015; 2) specimen from 2010HBSIIIT0619III②; 3) specimen from 12XBSIIIF003; 4) specimen from 2009HBSIIIT0719①; 5) specimen from 11XBSIIIT0720IV-2②; 6) specimen from 2010HBSIIIT0720I③. The close-ups at the bottom show polished tips of the awls (Left: specimen from 2009HBSIIIT0719①; Right: specimen from 2010HBSIIIT0720I③).

Fig 7. Examples of bone tools from Shirenzigou.

1) specimen from 12XBSIIIT0720II-2③; 2) specimen from 2009HBSIIIT0822④; 3) specimen from 2010HBSIIIT0819IV①; 4) specimen from 2010HBSIIIT0720I②; 5) specimen from 2011XBSIIIDM4.

Fig 8. Examples of bone arrowheads from Shirenzigou.

1) specimen from 2009HBSIIIT0719③; 2) specimen from 2010HBSIIIM003④; 3) specimen from 2007BSDIVM013; 4) specimen from 2010HBSIIIM003⑤; 5) specimen from 2010HBSIIIM003④; 6) specimen from 2007BSDIVM013.

Fig 9. Bone plates unearthed from house F002 at Shirenzigou.

Fig 10. Examples of bone plates from Shirenzigou.

1) specimen from 2010HBSIIIT0620II②; 2) specimen from 12XBSIIIT0720IIIH025; 3) specimen from 12XBSIIIT0721II-2②; 4) specimen from 12XBSIIIT0720IIIH020; 5) specimen from 2010HBSIIIT0620II③; 6) specimen from 2010HBSIIIF004④; 7) specimen from 12XBSIIIF006; 8) specimen from 2010HBSIII-P2③.

Fig 11. Examples of worked caprine astragali from Shirenzigou.

1) specimen from 2009HBSIIIF002④; 2) specimen from 2009HBSIIIT0719③; 3) specimen from 2010HBSIIIM003②; 4) specimen from 2010HBSIIIT0719IV③; 5) specimen from 2010HBSIIIM003④; 6) specimen from 2010HBSIIIT0720I④; 7) specimen from 12XBSIIIT0720IIIH020; 8) specimen from 2010HBSIIIT0619III②.

Fig 12. Worked caprine astragali from house F002 at Shirenzigou.

Fig 13. Animal taxonomic structure for worked bones from Shirenzigou.

Fig 14. Raw material selection for the six categories of worked bones from Shirenzigou.