 In 1988, fossils of sea cows were discovered in Hokkaido, but were originally assigned to the Takikawa sea cow ("H. spissa"), a newly described species, but this is thought of by some scientists as a synonym of "H. cuestae".It is uncertain whether or not "H. spissa" was simply a local variant of "H. cuestae" or a completely separate lineage.The Steller's sea cow was apparently a direct descendant of the Cuesta sea cow.