Equus (genus)
Equus is a genus of mammals in the family Equidae, which includes horses, donkeys, 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. The genus most likely originated in North America and spread quickly to the Old World. Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes (erect in most subspecies), and long tails. All species are herbivorous, and mostly grazers, with simpler digestive systems than ruminants, but able to subsist on lower-quality vegetation.
Northeast Ecological Corridor
Of the eight reptilian families present in the NEC, gecko and anoles have the largest number of species. The first includes two geckos, and three salamanquita geckos, the second family consists of five lizard species. Of the total number of reptilian species documented at the NEC, 11 are endemic, five native and two introduced. An introduced iguana species and two types of boa have also been sighted. Two freshwater turtles and two species of sea turtles live in this area: the hawksbill ("Eretmochelys imbricata") and the leatherback ("Dermochelys coriacea"), the latter which has become the emblematic species of the NEC. Of the exotic species found in the NEC the green iguana ("Iguana iguana") stands out. This reptile is native to Central and South America, and introduced to Puerto Rico in the early 1970s by pet stores. Currently they are considered a pest.