为探索安徽华龙洞遗址大额牛的食性以及生态环境背景，本文对遗址中出土的6颗大额牛牙齿化石进行了牙结石植硅体分析及牙釉质稳定同位素分析等研究。结果显示，华龙洞地区的大额牛主要以不同高度的草本植物为食；牙结石中的诊断性植硅体形态鉴定结果表明，姜目和禾本科植物是大额牛饮食的重要组成部分；大额牛牙齿样本的δ¹³C值在-10.3‰~-4.6‰，平均约-8.6‰，指示其食用的植物类型以C₃植物为主，少量C₄植物为辅。综合其食性及其化石常发现的地点，推测华龙洞遗址的大额牛生存于森林较疏朗地带，且食谱中姜目植物的发现也暗示其生存于温暖的气候背景中。本研究结果为了解华龙洞遗址大额牛的食性、栖息地以及气候背景提供了新的植物微体化石与同位素记录，也为重建安徽地区中更新世的古环境提供了依据。

The Hualongdong site in Dongzhi County, Anhui Province, represents the most comprehensive Paleolithic site in China since Zhoukoudian, yielding abundant hominin fossils alongside stone tools and other evidence of human activities. Notably, it has also produced a substantial assemblage of mammalian fossils. As a key species in China's Quaternary mammalian fauna, the Pleistocene gaur [Bos (Bibos) sp.] shares close phylogenetic relationships with its extant counterparts. However, systematic understanding of this fossil Bos (Bibos) sp. species remains limited due to fragmentary fossil materials and methodological constraints. The dental fossils of Bos (Bibos) sp. from Hualongdong site provide crucial materials for investigating its dietary habits, ecological niche, paleoenvironment and ecosystem. This study employs multidisciplinary approaches including CT three-dimensional modeling, phytolith analysis, and stable isotope analysis to systematically investigate Bos (Bibos) sp. dental fossils. CT modeling precisely identified dental calculus locations, enabling subsequent phytolith extraction and morphological characterization from calculus deposits. Concurrently, carbon stable isotope analysis was conducted on tooth enamel. Results reveal that the late Middle Pleistocene Hualongdong site Bos (Bibos) sp. feed on herbaceous plants of varying heights. Carbon isotope data indicate a primary reliance on C₃ plants from the site and surrounding areas, supplemented by limited C₄ plant consumption (δ¹³C values: -10.3‰ to -4.6‰). Phytolith analysis specifically indicates frequent ingestion of Poaceae and Zingiberales species. These findings collectively indicate that Bos (Bibos) sp. primarily foraged in warm environments dominated by C₃ vegetation during the late Middle Pleistocene. The diverse phytolith assemblages and isotopic signatures reflect rich regional vegetation heterogeneity, providing ample food resources. Furthermore, the common occurrence of Pleistocene Bos (Bibos) sp. fossils in alluvial plains, mountain valleys, and karst caves suggests their preference for open forest areas with grassy patches. This ecological pattern aligns with their mixed dietary strategy of feeding on both C₃ and C₄ plants. This research establishes novel phytolith and isotopic records for understanding Bos (Bibos) sp. paleodietary ecology while contributing to Middle-Late Pleistocene paleoclimatic and paleoecological reconstructions in Anhui Province. The integrated methodology demonstrates the efficacy of combining Plant microfossils and geochemical proxies in paleodietary studies, offering insights into herbivore-environment interactions during the Pleistocene.