What animal with only four extant species was the name borne by four ships of the Royal Navy
Hyena Hyenas or hyaenas (from Greek ὕαινα "hýaina") are any feliform carnivoran mammals of the family Hyaenidae . With only four extant species, it is the fifth-smallest biological family in the Carnivora, and one of the smallest in the class Mammalia. Despite their low diversity, hyenas are unique and vital components of most African ecosystems.
HMS Janus Six ships of the Royal Navy have borne the name HMS "Janus", after Janus, the two-faced God of Roman mythology: