Word Origin and History for semi-Expand before vowels sem-, word-forming element meaning half, part, partly; partial, imperfect; twice, from Latin semi-half, from PIE *semi-half (cf. Sanskrit sami half, Greek hemi-half, Old English sam-, Gothic sami-half).
Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, hamsters, gerbils and capybaras. Other animals such as rabbits, hares, and pikas, whose incisors also grow continually, were once included with them, but are now considered to be in a separate order, the Lagomorpha.
Equus is a genus of mammals in the family Equidae, which includes horses, asses, and zebras.Within Equidae, Equus is the only recognized extant genus, comprising seven living species. The term equine refers to any member of this genus, including horses.Like Equidae more broadly, Equus has numerous extinct species known only from fossils.itochondrial evidence supports the division of Equus species into non-caballoid (which includes zebras and asses) and caballoids or true horses (which includes E. ferus and E. przewalskii).