What is "water opossum"

Yapock \Ya"pock\ (?; 277), n. [Probably from the river Oyapok, between French Guiana and Brazil.] (Zo["o]l.) A South American aquatic opossum ( Chironectes variegatus) found in Guiana and Brazil. Its hind feet are webbed, and its fore feet do not have an opposable thumb for climbing. Called also water opossum. [Written also yapack.]

n. A marsupial found in Central and South America, (taxlink Chironectes minimus species)

The water opossum (Chironectes minimus), also locally known as the yapok , is a marsupial of the family Didelphidae. It is the only living member of its genus, Chironectes. This semiaquatic creature is found in and near the freshwater streams and lakes in Mexico, Central and South America to Argentina, and is the most aquatic living marsupial (the lutrine opossum also has aquatic habits). It is also the only living marsupial in which both sexes have a pouch. The thylacine, commonly referred to as the Tasmanian tiger, also exhibited this trait, but is now believed to be extinct.

The animal lives in bankside burrows, emerging after dusk to swim and search for fish, crustaceans and other aquatic animals, which it eats on the bank.