Noun
An order of large aquatic herbivorous mammals, including the manatee, dugong, rytina, and several fossil genera.
Source: Webster's dictionaryThey only occur on about 20% of all placentalian mammal species, and are unknown from several orders of mammals (Monotremata, Edentata, Pholidota, Chiroptera, Cetacea, Sirenia and Proboscidea). Source: Internet
Heptner, "Sirenia and carnivora (Sea cows; Wolves and Bears)" They are generally dark with a light tip, with some forms having completely light claws. Source: Internet