The stapes is the smallest bone of the mammalian skeleton. Being the innermost middle ear ossicle, it is in contact with the inner ear and is directly responsible for sound transmission into it. Today, Ruminantia are one of the most diversified groups of large mammals with more than 200 species. However, their stapes has been very little studied. Here we investigate the shape of 66 stapes from 44 species of extant and extinct Ruminantia, including intra-individual and intra-specific observations, based on 3D tomographic data. Shape differences and similarities are quantitatively discussed thanks to 3D geometric morphometrics. The overall size of the stapes scales with a negative allometry in comparison to body mass. Moreover, the overall shape of the stapes informs about phylogeny. A trend is observed from a concave posterior crus with an enlarged stapes capitulum in Antilocapridae to a relatively straight posterior crus with a little reduced stapes capitulum in Cervidae, Bovidae being intermediate. In addition, the stapes of Antilocapridae is relatively trapezoid in lateral view; that of Cervidae is more triangular in lateral view; and that of Bovidae is relatively rectangular in lateral view. The stapedial footplate shape also gives phylogenetic information. The Tragulidae stapedial footplate is antero-posteriorly asymmetrical. The stapedial footplate is ovoid in stem Pecora. It is asymmetrical in Bovidae, while it is more symmetrical in Cervidae. This is in agreement with previous studies on the ruminant bony labyrinth showing that the oval window, the counterpart of the stapedial footplate on the inner ear, bears a strong phylogenetic signal already distinguishable in early Miocene ruminants.

骨是哺乳动物骨骼中最小的骨头。作为中耳最里面的小骨，它与内耳接触并直接负责将声音传输到内耳中。如今，反刍动物是拥有200多种物种的大型哺乳动物中最多样化的群体之一。然而，对其骨的研究很少。在这里，我们根据3D断层扫描数据，调查了来自44种现存和已灭绝的杜鹃花的66种骨的形状，包括个体内和种内观察。由于3D几何形态计量学，对形状差异和相似性进行了定量讨论。body骨的整体大小与体重相比呈负向异形。此外，骨的整体形状说明了系统发育。观察到一种趋势，从Anticapcapridae中的凹后足具增大的pes骨头盖处，到相对直的后壳，其在Cervidae中具少量reduced骨cap的头盖骨，Bovidae处于中间。此外，从侧面看，钩cap科的the骨相对梯形；从侧面看鹿角科的三角形更三角形；牛科在侧面看是相对矩形的。骨足板的形状也提供了系统发育信息。Tragulidae foot足踏板在前后不对称。Pe足柄中的骨足板为卵形。它在牛科中不对称，而在鹿科中更对称。这与反刍动物的迷宫迷路的先前研究一致，该研究表明椭圆形窗口是内耳上的骨足踏板的对应物，