Horse
The horse adapted to survive in areas of wide-open terrain with sparse vegetation, surviving in an ecosystem where other large grazing animals, especially ruminants, could not. Horses and other equids are odd-toed ungulates of the order Perissodactyla, a group of mammals that was dominant during the Tertiary period. In the past, this order contained 14 families, but only three—Equidae (the horse and related species), Tapiridae (the tapir), and Rhinocerotidae (the rhinoceroses)—have survived to the present day.
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.