Dugesiidae Ball, 1974

It is very likely that Dugesiidae is the best-known freshwater flatworm family among the non-specialist. Dugesiids are popular due to the recognizable triangle-shaped head that many of the family representatives present and due to their astounding regeneration capabilities. The family was erected in 1974 by Ian R. Ball and then included Dugesia, Cura, Bopsula, and possibly (sic) Rhodax. At the present, twelve genera are referred to Dugesiidae: Bopsula, Cura, Dugesia, Eviella, Girardia, Neppia, Recurva, Reynoldsonia, Romankenkius, Schmidtea, Spathula, and Weissius. The family has a wordwide distribution, excepting the Antarctica.

According to molecular phylogenetic results, Dugesiidae is the sister group of Geoplanidae or land planarians family. However, it is not clear whether Dugesiidae is a monophyletic family because some of its representatives (i.e. Spathula and Romankenkius) are phylogeneticaly closer to the land planarians than to the other Dugesiidae genera (Álvarez-Presas et al., 2008).

The type-genus of this family is Dugesia Girard, 1850.