Although they may resemble shrews, hedgehogs, or otters, they are not closely related to any of these groups. Their closest relatives are other African, insectivorous mammals such as golden moles and elephant shrews. The common ancestry of these animals, together with aardvarks, hyraxes, elephants, and sea cows in the group Afrotheria, was not recognized until the late 1990s. Work on the diversity of afrotherian mammals has provided more support for their common ancestry.