为了确定太行山猕猴(Macaca mulatta)的椎动脉沟上3种骨桥（腹桥、侧桥和背桥）的分布特征，以期理解在人类寰椎上观察到的变异，并推测灵长类动物可能的进化趋势。本文分别测量57例（雄性17例，雌性40例）猕猴寰椎标本（成年骨骼标本）3个寰椎桥的宽度。并采用SPSS统计软件进行数据处理，性别之间差异采用方差分析，观察寰椎桥的出现率、形态特征和组合类型。统计结果显示，猕猴寰椎桥变量性差显著(P<0.05)，猕猴的腹桥和背桥是恒定出现(100%)，侧桥基本恒定，但也有一些缺失个案(90.3%)，表明腹桥和背桥是猕猴稳定的特征；猕猴寰椎桥的主要类型为原始的A型，与主要类型为D型的人科动物发生分离。我们基于以上特征后得出结论，猕猴的3个寰椎桥是一种稳定性状，其出现率明显高于类人猿。

There may be three kinds of bone bridges on the vertebral artery sulcus of Macaca mulatta in Taihang Mountains, which are ventral bridge, lateral bridge and dorsal bridge. This paper explores their distribution characteristics. It is helpful for us to speculate on evolutionary trends in primates. It also has important clinical significance for people to understand the variations observed in the human atlas. It focuses on observing those non-measured and measured characteristics of the atlas bridge of Macaca mulatta in Taihang Mountains, and count its lateral differences, gender differences and population differences. Based on such research significance and research focus, this paper selects a total of 57 specimens (adult bone specimens) (male 17, female 40) of the atlas bridge of Macaca mulatta. For each atlas specimen, the width of three possible atlas bridges located on the vertebral artery sulcus is measured and analyzed. Firstly, observe and describe its morphology, and accurately observe and count the bridge widths of the atlas ventral bridge, lateral bridge and dorsal bridge; Then, SPSS statistical software was used to process the previously obtained measurement data and observe the occurrence rate, morphological characteristics, and combination types of the atlas bridge; Finally, further explore the possible influencing factors that may occur during the evolutionary process of the atlas bridge in primates. The statistical results show that the variability of the atlas bridge in macaques is significantly different (P<0.05), and the ventral and dorsal bridges are constant (100%), while the lateral bridges are basically constant. However, there are also some missing cases (90.3%), indicating that the ventral and dorsal bridges are stable characteristics of Macaca mulatta; The main type of atlas bridge in Macaca mulatta is the primitive type A, which is separated from the main type D of human animals. Based on the above characteristics, we conclude that the three atlas bridges of macaques are a stable trait with a significantly higher incidence than those of apes. In addition, this article categorizes the atlas bridge types of primates, which can provide reference suggestions for researchers to speculate on the corresponding population evolution degree.