After O'Leary, 1998a, b

<==o Mesonychia Van Valen, 1966 [Acreodi] (mesonykit; mesonychians)
   |--o †Hapalodectidae Ting & Li 1987
   |  |--o †Hapalodectes Matthew, 1909
   |  |  |?- †H. hetengensis
   |  |  |-- †H. anthracinus Zhou & Gingerich, 1991
   |  |  |-- †H. dux Lopatin, 2001
   |  |  `-- †H. leptognathus (Osborn & Wortman, 1892) [H. compressus]
   |  `--+-- †Hapalorestes lovei Gunnell & Gingerich, 1996
   |     `--+-- †Metahapalodectes Dashzeveg, 1976
   |        `--+-- †Lohoodon Chow et al., 1973
   |           `-- †Honanodon hebetis Chow, 1965
   `--o †Mesonychidae Cope, 1875
      |?- †Lihoodon [=? Lohoodon??]
      |?- †Plagiocristodon
      |-- †Yantanglestes
      `--+--o †Hukoutherium Chow et al., 1973
         |  |-- †H. ambigum Chow et al., 1973
         |  `-- †H. shimemensis Qi & Huang, 1982
         `--+-- †Dissacusium Zhou et al., 1977
            `--+--o †Dissacus Cope, 1881b [Hyaenodictis]
               |  |-- †D. argenteus O'Leary & Rose, 1995
               |  |-- †D. navajovius (Cope, 1881) [D. carnifex]
               |  |-- †D. praenuntius Matthew, 1915
               |  |-- †D. serior O'Leary & Rose, 1995
               |  `-- †D. willwoodensis O'Leary & Rose, 1995
               `--+-- †Ankalagon saurognathus (Wortman 1897) [non Matthew, 1897?) Van Valen, 1980
                  `--+-- †Sinonyx jiashanensis Zhou, Zhai, Gingerich & Chen, 1995
                     `--+--o †Pachyaena Cope, 1874
                        |  |-- †P. gracilis (Matthew, 1915)
                        |  |-- †P. ossifraga Cope, 1874 [incl. P. intermedia (Wortman, 1892)]
                        |  `-- †P. gigantea (Osborn & Wortman, 1892)
                        `--+-- †Jiangxia
                           `--+-- †Hessolestes ultimus
                              `--+--o †Synoplotherium Cope, 1872a [Dromocyon]
                                 |  |-- †S. canius
                                 |  `-- †S. vorax (Marsh, 1876c)
                                 `--+-- †Mesonyx obtusidens Cope, 1872a
                                   `--+-- †Mongolonyx
                                      `--+-- †Guilestes Zheng & Chi, 1978
                                         `--+-- †Mongolestes
                                            `--o †Harpagolestes Wortman, 1901
                                               |?- †H. orientalis
                                               |-- †H. brevipes Thorpe, 1923
                                               |-- †H. immanis Matthew, 1909
                                               |-- †H. leotensis Peterson, 1931
                                               |-- †H. macrocephalus Wortman, 1901
                                               `-- †H. uintensis (Scott & Osborn, 1887)

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