After McKenna & Bell, 1997, and Alroy, 2002

Psittacotherium Cope, 1882
        non †Hemicanus Wortman, 1897

        †Psittacotherium multifragum Cope, 1882
            †Hemiganus vultuosus Cope, 1882
              = † Psittacotherium multifragum (Cope); Wortman, 1897, Matthew, 1937, Schoch, 1981a, and Schoch, 1986
            †Psittacotherium aspasiae Cope, 1882; Matthew, 1937, Wortman, 1897, Schoch, 1981a, and Schoch, 1986
              = †Psittacotherium multifragum Cope; Lucas et al., 1998
            †Psittacotherium megalodus Cope; 1887
              = †Psittacotherium multifragum Cope; Wortman, 1897, Schoch, 1981a, and Schoch, 1986

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