 In 1961 , Cabrera listed both spegazzinii and tucumanensis as subspecies of Akodon boliviensis , with alterus as a full synonym of A. boliviensis tucumanensis . In 1990 , Philip Myers and colleagues reviewed the Akodon boliviensis species group . They provisionally kept Akodon spegazzinii as a species separate from A. boliviensis , with tucumanensis as a subspecies , and suggested that alterus was likely related to spegazzinii and tucumanensis . Subsequently , the treatment of these species in systematic works became variable . A 1992 paper suggested that alterus and tucumanensis were , at best , very similar to each other , but in 1997 , Michael Mares and colleagues listed each of the three as distinct species in a compendium of the mammals of Catamarca , citing differences in habitat and fur coloration . They were followed by Mónica Díaz and Rubén Bárquez in 2007 , among others . However , in 2000 Díaz and colleagues listed alterus and tucumanensis as subspecies of spegazzinii in a review of the mammals of Salta . Guy Musser and Michael Carleton , in the 2005 third edition of Mammal Species of the World , also considered the three to represent the same species , as did Ulyses Pardiñas and colleagues in a 2006 review of Argentinean Akodontini . Meanwhile , Carlos Galliari and Pardiñas had recognized Akodon leucolimnaeus as a true Akodon , not a Necromys , in 1995 . Although associated with the Akodon boliviensis group , its precise status remained unclear . The common name " Catamarca akodont " was proposed for this species . 
