Order Testudines Wagler, 1830 - turtles
   Suborder Cryptodira Cope, 1868
     Superfamily Trionychoidea Gray, 1825
       Family Trionychidae Gray, 1825 - softshell turtles
         Subfamily Trionychinae Gray, 1825
           Genus Apalone Rafinesque, 1832
             Apalone spinifera (LeSueur, 1827) - spiny softshell turtle
               1 Apalone spinifera spinifera (LeSueur, 1827) - northern spiny softshell turtle
               2 Apalone spinifera aspera (Agassiz, 1857) - Gulf Coast spiny softshell turtle
               3 Apalone spinifera atra (Webb & Legler, 1960) - black spiny softshell turtle
               4 Apalone spinifera emoryi (Agassiz, 1857) - Texas spiny softshell turtle
               5 Apalone spinifera guadalupensis (Webb, 1962) - Guadalupe spiny softshell turtle
               6 Apalone spinifera pallida (Webb, 1962) - pallid spiny softshell turtle