For more than a century, the orbital angle has been studied by many authors to distinguish dog skulls from their progenitor, the wolf. In early studies, the angle was reported to be different between dogs (49°–55°) and wolves (39°–46°). This clear difference was, however, questioned in a more recent Scandinavian study that shows some overlap. It is clear that in all studies several methodological issues were unexplored or unclear and that group sizes and the variety of breeds and wolf subspecies were small. Archaeological dog skulls had also not been studied. Our goal was to test larger and more varied groups and add archaeological samples as they are an evolutionary stage between wolves and modern dogs. We also tested the influence of measuring methods, intra- and inter-reliability, angle symmetry, the influence of variations in skull position and the possibility of measuring and comparing this angle on 3D CT scan images. Our results indicate that there is about 50 % overlap between the angle range in wolves and modern dogs. However, skulls with a very narrow orbital angle were only found in wolves and those with a very wide angle only in dogs. Archaeological dogs have a mean angle very close to the one of the wolves. Symmetry is highest in wolves and lowest in archaeological dogs. The measuring method is very reliable, for both inter- and intra-reliability (0.99–0.97), and most skull position changes have no statistical influence on the angle measured. Three-dimensional CT scan images can be used to measure OA, but the angles differ from direct measuring and cannot be used for comparison. Evolutionary changes in dog skulls responsible for the wider OA compared to wolf skulls are mainly the lateralisation of the zygomatic process of the frontal bone. Our conclusion is that the orbital angle can be used as an additional morphological measuring method to discern wolves from recent and archaeological dogs. Angles above 60° are certainly from recent dogs. Angles under 35° are certainly of wolves.

中文翻译：

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眼眶角形态可以区分狗和狼吗？

一个多世纪以来，许多作者一直在研究轨道角，以区分狗的头骨和它们的祖先狼。在早期研究中，据报道狗（49°–55°）和狼（39°–46°）的角度不同。然而，这种明显的差异在最近的斯堪的纳维亚研究中受到质疑，该研究表明存在一些重叠。很明显，在所有研究中，有几个方法论问题尚未探索或不清楚，而且群体规模、品种和狼亚种的种类都很小。考古狗头骨也没有被研究过。我们的目标是测试更大、更多样化的群体，并添加考古样本，因为它们是狼和现代狗之间的进化阶段。我们还测试了测量方法、内部和内部可靠性、角度对称性、头骨位置变化的影响以及测量和比较该角度对 3D CT 扫描图像的可能性。我们的结果表明狼和现代狗的角度范围之间有大约 50% 的重叠。然而，轨道角非常窄的头骨只在狼身上发现，而角非常宽的头骨只在狗身上发现。考古犬的平均角度非常接近其中一只狼。狼的对称性最高，考古犬的对称性最低。该测量方法非常可靠，对于内部和内部可靠性（0.99-0.97），大多数颅骨位置变化对测量的角度没有统计影响。3D CT扫描图像可用于测量OA，但角度与直接测量不同，不能用于比较。与狼头骨相比，导致更宽 OA 的狗头骨的进化变化主要是额骨颧突的侧化。我们的结论是，轨道角可以作为一种额外的形态学测量方法来区分狼和考古犬。60°以上的角度肯定来自最近的狗。35°以下的角度肯定是狼的。