The Pecora are a group of hoofed mammals that comprise most of the ruminants, including cattle, sheep, goats, antelopes, deer, giraffes, and pronghorns. The only extant members of the Ruminantia that are not pecorans are the chevrotains, which lack horns and whose four-chambered stomachs are less developed than those of the pecorans. This gives rise to the pecorans sometimes being called "horned ruminants". Pecorans are also known as "higher ruminants", because they arose more recently than other ruminant groups. Although Pecora is well-supported as a clade, the exact relationships among families within it are in dispute.
Flower, W.H. (1883). "On the arrangement of the orders and families of existing Mammalia". Proceedings of the Zoological Society of London1883: 178–186.
Hassanin, Alexandre, & Douzery, Emmanuel J. P. (2003). "Molecular and morphological phylogenies of Ruminantia and the alternative position of the Moschidae". Systematic Biology52 (2): 206–228. doi:10.1080/10635150390192726. PMID12746147.