What is Equus (genus)?
{{italictitle}} '''''Equus''''' is a [[genus]] of [[mammals]] in the [[family (biology)|family]] [[Equidae]]. It includes [[horse]]s, [[donkey|asses]], and [[zebra]]s. ''Equus'' is the only living ([[Extant taxon|extant]]) genus of horses, and there are seven living [[species]]. They are the one-toed horses, and are [[adapted]] for living in various types of [[grasslands]]. The term '''equine''' refers to any member of this genus. ''Equus'' has many [[extinct]] [[species]] known only from [[fossil]]s. The genus most likely originated in [[North America]] and spread quickly to the [[Old World]]. Equines are [[odd-toed ungulate]]s with slender legs, long heads, relatively long necks, manes (erect in most subspecies) and long tails. All species are [[herbivorous]], and mostly [[grazing|grazers]] with simpler [[digestive system]]s than [[Ruminantia|ruminants]]. They can live on low-quality vegetation. [[Feral]] equine populations are widespread, but wild equines are found only in [[Africa]] and [[Asia]]. Wild populations may have a [[harem]] system. In this case one adult male or ''stallion'', several females or ''mares'' and their young or ''foals''. Otherwise they live in a territory where males control territories with resources that attract females. In both systems, females take care of the foals, though males may play a role as well. Equines communicate with each other visually and vocally. Human activities have threatened wild equine populations and out of the seven living species, only the [[plains]] zebra is still widespread and abundant. The one-toed horses of the grasslands developed from smaller three-toed horses which lived more in forests and wooded savannahs. Before the coming of humans, horses were much more varied and widespread, though the number of species is not known.<ref>Weinstock J. ''et al'' 2005. Evolution, systematics, and phylogeography of Pleistocene horses in the New World: a molecular perspective. ''PLoS Biology''. '''3''' (8): e241. [http://journals.plos.org/plosbiology/article?id=10