Manatees and dugongs are marine mammals of the order Sirenia. They originated in the middle Eocene period around 45 to 50 million years ago. They are gentle, plant-eating herbivores sometimes nicknamed sea cows.
Interesting posts about this link
nwfloaBeverly HillI've suspected for some time that manatees communicated in the infrasonic range
equillErin QuillInfluentialManatees are the hippies of the sea; vegetarians & peaceful drifters RT @EcoInteractive:Science for Protecting Manatees http://bit.ly/h3CSUJ