In 2012, many species classified as Quadrula were moved to Rotundaria and Theliderma based on genetic and morphological evidence.[1]
Species currently in Quadrula now consist of:[2]
^Campbell, David; Lydeard, Charles (2012). "The Genera of Pleurobemini (Bivalvia: Unionidae: Ambleminae)". American Malacological Bulletin. 30 (1): 19–38.