Sheep skulls replicas. Museum Quality. Bighorn Sheep Skull. Merino Ran Skull. Domestic Sheep Skull. Domestic sheep (Ovis aries) are quadrupedal, ruminant mammals kept as livestock. Like all ruminants, sheep are even-toed ungulates, also commonly called cloven-hoofed animals. Although the name "sheep" applies to many species, in everyday usage it almost always refers to Ovis aries. Domestic sheep are the most numerous species in their genus, and are most likely descended from the wild Mouflon of Europe and Asia.