 In 1893 three species were assigned to the group "Pezophaps solitarius", "Didus ineptus", and the possible species "Didus borbonicus".Today, only two raphine species are known, with "Didus ineptus" becoming a junior subjective synonym of "Raphus cucullatus"; "Didus?borbonicus" now classified as the ibis "Threskiornis solitarius"; and "Didus nazarenus" being identified as synonymous with "Pezophaps solitarius".