Fig. 3.

Facial shape variation and brachycephaly in domestic ruminants. Certain varieties and breeds of sheep (A; Valais Blacknose sheep) and goats (B; breed unknown, Bangalore, India) exhibit a convex profile of the nose, which is termed “roman nose” (shown as a dashed line in panel C). These variations are mostly relatively mild and do not result in discordance between maxilla and mandible length, as shown on the example of the skull of a Valais Blacknose sheep (C; Musée de la Nature du Valais, Switzerland; HN 2010511). However, in certain goat varieties and breeds, such as Jamnapari/Etawah goats (D), extreme “roman nose” may be associated with an overshot lower jaw and dental malocclusion. The overshot lower jaw and dental malocclusion (dashed circles in panel E) are shown on the example of the skull of an “Egyptian goat” (E; “Ägyptische Ziege”; Naturmuseum Wien, Austria; NMW 2074). These varieties/breeds could be classified as “katantognathic” brachycephalic, where, in addition to the extremely convex nasal bones, parts of the snout (premaxilla) are foreshortened and downward tilted (Fig. 1 and Table 1). In other domestic ruminants, such as cattle, no cases of “katantognathic” brachycephaly are known. Instead, the extinct Niata cattle from South America (F, reconstruction) is characterized by shortened and upward tilted facial bones (G), which is indicative of “bulldog-type” brachycephaly (Fig. 1), and may also lead to dental malocclusion (G). Pictures are not to scale. Credits: A, Benjamin Jost; B, C, E: Madeleine Geiger; D, Shutterstock: Ibenk_88; F, G: Artwork by Jorge González.