It is the only extant member of the family, Zaproridae.

The genus, in turn, contains the only extant member of the family Dermochelyidae.

It is the only extant member of the genus Ophiodon.

The extant members are apparently remnants of a formerly diverse and widespread order.

Together, these two species comprise the only extant members of the Monodontidae family, sometimes referred to as the "white whales".

It was smaller than the two extant members of its genus.

The spotted hyena is the largest extant member of the Hyaenidae.

The common term nautilus usually refers to any extant members of the Nautilidae family.

It is the only extant member of its genus, although other fossil species have been described.

Killer whales are the largest extant members of the dolphin family.