 "Sphaerium nucleus" was described by Studer 1820, who placed it in the genus "Cyclas".It was later thought to be a subspecies of "Sphaerium corneum".Subsequently it was raised to a full species again as "Sphaerium nucleus" (Studer, 1820) due to its having a different form of kidney, and the shell having a broad hinge plate, dense porosity and more tumid shells with broad umbones.