The name manatee comes from the Spanish manatí, which itself comes from a Caribbean word meaning breast. Florida manatees are large, aquatic mammals that are native to Florida – a sub-species of the West Indian manatee (Trichechus manatus). The manatee is a large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. Sea cows, comes from the fact that they are slow plant-eaters, peaceful and similar to cows on land. Manatees are three of the four living species in the order Sirenia – thought to have evolved from four-legged land mammals more than 60 million years ago. The fourth is the Eastern Hemisphere's dugong. there are three species of manatee: the Amazonian manatee (Trichechus inunguis); the West Indian manatee, or the American manatee (Trichechus manatus); and the African manatee (Trichechus senegalensis). Their names indicate the regions in which they live.