Class Mammalia Linnaeus, 1758 - mammals Subclass Theria Parker & Haswell, 1897 Order Sirenia Gill, 1872 - sea cows Family Trichechidae Gill, 1872 - manatees Genus Trichechus Linnaeus, 1758 - manatees Trichechus inunguis (Natterer, in Pelzeln, 1883) - Amazon manatee