After carroll, 1988, and Lapparent de Broin, 2000

<==o †Thalassemyidae Rütimeyer, 1878
   |-- †Desmemyss Wegner, 1911 [a pleurosternid?]
   |-- †Padiochelys [?Chelonemys]
   |--o †Thalassemys Rütimeyer, 1859
   |  |-- †T. carva Nessov, 1984
   |  |-- †T. hugii Rütimeyer, 1873 [Thalassemys gresslyi Rütimeyer, 1873]
   |  `-- †T. moseri Bräm, 1965 [on skull characters (Gaffney & Meylan, 1988) (Milner, 2004)]
   |--o †Tropidemys Rütimeyer, 1873
   |  |-- †T. langi Rütimeyer, 1873 [Tropidemys expansa Rütimeyer 1873, Tropidemys gibba Rütimeyer, 1873]
   |  |-- †T. morinica Sauvage, 1880
   |  `-- †T. seebachi Portis, 1878
   `-- †Yaxartermys

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