Manatees (family.. Trichechidae, genusTrichechus) are large, fully aquatic marine mammals sometimes known as sea cows. The name manatí comes from the Taino which are the original peoples of the Caribbean, meaning "breast". They comprise three of the four living species in the order Sirenia, the other being the dugong, which is native to the Eastern Hemisphere.
The Sirenia is thought to have evolved from four-legged land mammals
over 60 million years ago, with the closest living relatives being the Proboscidea (elephants) and Hyracoidea (hyraxes).