Dugong
The dugong is a medium sized marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees.
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It is the only living representative of the once diverse family Dugongidae, its closest modern relative, Stellers sea cow, was hunted to extinction in the 18 th century. The dugong is the only strictly marine herbivorous mammal.
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Dugongs, along with other sirenians, are referred to as sea cows because their diet consists mainly of sea grass. When eating they ingest the whole plant, including the roots, although when this is impossible they will feed on just the leaves.