PlesiochelyidaeXinjiangchelysSinemydidaeChelydridaeChelomacryptodiraToxochelysCtenochelysOsteopygisPuppigerusChelonia_mydasSantanachelysNotocheloneDesmatochelysChelosphargisProtostega_gigasCorsochelysMesodermochelysDermochelysOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Hirayama_1998a