Borges, Sonia. (1992). A tentative phylogenetic analysis of the genus Pontoscolex (Oligochaeta : Glossoscolecidae) [sic, currently in family Rhinodrilidae]. Soil Biology and Biochemistry. 24 (12): 1207-1211.
A phylogenetic analysis of the species of Pontoscolex has been made using PAUP with a data matrix of 15 characters. The results support Righi Zoologische Mededelingen Leiden 43, 314–315, 1984) and Borges and Moreno (Bolletino del Museo Regionale di Scienze Naturali Torino,1992 [sic for 1990]) in their division of the genus into three subgenera, but challenge the diagnostic criteria used by Righi and the evolutionary implications of Borges and Moreno. The subgenera are redefined.