Mulvey, M., C. Lydeard, D.L. Pyer, K.M. Hicks, J. Brim-Box et al. 1997. Conservation genetics of North American freshwater mussels Amblema and Megalonaias. Conservation Biology 11(4): 868-878. Available electronically.
(click the figure number to see the cladogram)
+----------- Utterbackia_imbecillis
--+
| +-------- Megalonaias_nervosa
+--+
| +----- Amblema_plicata
+--+
| +-- Amblema_neislerii
+--+
+-- Amblema_elliottii