Pfeiffer, J.M., A.E. Sharpe, N.A. Johnson, K.F. Emery & L.M. Page. 2018. Molecular phylogeny of the Nearctic and Mesoamerican freshwater mussel genus Megalonaias. Hydrobiologia 811: 139-151. Available electronically.
(click the figure number to see the cladogram)
+-------- Quadrula_quadrula
--+
| +----- Uniomerus_declivis
+--+
| +-- Megalonaias_nervosa
+--+
+-- Megalonaias_nickliniana