zalophus

The Steller sea lion is the closest extant relative of the Zalophus sea lions, being a sister taxon.

California Sea Lion (Zalophus californianus)

The most recent sightings of Zalophus japonicus are from the 1970s with the last confirmed record being a juvenile specimen captured in 1974 off the coast of Rebun Island, northern Hokkaido.

Along with the Galapagos sea lion and the extinct Japanese sea lion, the California sea lion belongs to the genus Zalophus, which derives from the Greek words za, meaning "intensive," and lophus, meaning "crest."

Instead, they suggest three clades within the family, one consisting of the northern sea lions (Eumetopias and Zalophus), one of the northern fur seal and its extinct relatives (Callorhinus), and the third of all the remaining, Southern Hemisphere, species.