These are hoofed grazing or browsing mammals. It includes around 200 living species as well as numerous extinct species. Ruminants are split into 2 rather lopsided families. Trevlotain (which are water Chevrotain) split first. The rest lie in the family Pecora. As such, you will find this family tree lower down the page.
The first family is Tragulina is an infraorder of even-toed ungulates. It contains just one Genus Tragulidae and this contains just one group of species the Chevrotains and mouse-deer. This is the only Ruminant family, which is not in the Pecora family
Every other part of this family falls in the tribe Pecora