Sirenians are lumbering aquatic animals that live in tropical and sub-tropical waters and whose closest relative is the elephant. Just four Sirenian species live today — three manatee species that live in different coastal waters of the Atlantic Ocean, and one species of dugong, which is found along the coasts of the Indo-Pacific Ocean — known collectively as sea cows. The now-extinct Stellar sea cow (Hydrodamalis) roamed the Eastern Pacific coast until around 1770 when the last of these were hunted to extinction by American explorers, according to the University of California, Museum of Paleontology (UCMP).
The West Indian manatee (Trichechus manatus) is currently in danger of going extinct. In the U.S., the manatee can be found around Florida during winters and as far west as Louisiana during summer months. Their range extends throughout the Caribbean Sea.
This dugong is one of four seacow, or Sirenians, species in the world. They all live in different coastal areas of the ocean.
Manatees swim at Blue Springs State Park in Orange City, Fla., on Thursday, Jan. 5, 2006. 2005 was a hard one for the state's endangered manatee population. The number of confirmed manatee deaths increased 30 percent in 2005. The largest known cause of death is collisions with boats.
Underwater view of manatee surfacing
Three sets of sea cows lived in three different times and locations: the late Oligocene (23 million to 28 million years ago) in Florida, the early Miocene (16 million to 23 million years ago) in India and the early Pliocene (3 million to 5 million years ago) in Mexico.