1) Family dugongidae 2) Mammal family 
The Dugongidae are a family in the order of Sirenia. The family has one surviving species, the dugong (Dugong dugon), one recently extinct species, Steller`s sea cow (Hydrodamalis gigas), and a number of extinct genera known from fossil records. ==Taxonomy== The genera Eosiren, Eotheroides, and Prototherium have been assigned to Halitheriinae in ....
(from the article `dugong`) Dugongs are the only living members of the family Dugongidae. Dugongidae and the family Trichechidae (manatees) constitute the mammalian order ...
[n] - a family of mammals of order Sirenia including dugongs and Steller`s sea cow
family Dugongidae noun a family of mammals of order Sirenia including dugongs and Steller`s sea cow