Otter Otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the weasel family Mustelidae, which also includes badgers, honey badgers, martens, minks, polecats, and wolverines. The word "otter" derives from the Old English word "otor" or "oter". This, and cognate words in other Indo-European languages, ultimately stem from the Proto-Indo-European language root *wódr̥, which also gave rise to the English word "water". An otter's den is called a holt or couch. Male otters are called dogs or boars,
North American river otter the genus "Lutra"; "Lutra" was the early European name. The species name was "Lutra canadensis". The species epithet "canadensis" means "of Canada". In a new classification, the species is called "Lontra canadensis", where the genus "Lontra" includes all the New World river otters. Molecular biological techniques have been used to determine when the river otter and the giant otter ("Pteronura brasiliensis") of South America diverged. These analyses suggest they diverged in the Miocene epoch 23.03 to 5.33 million years ago (Mya), which is "much earlier" than indicated in the fossil record. Fossils of a giant river otter dating back 3.5