El género Tomarus Erichson (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) en Argentina, Chile yUruguay

The eight species in the genus Tomarus Erichson (Coleoptera: Scarabaeidae) in Argentina, Chile, and Uruguay are reviewed. Tomarus roigjunenti new species and Tomarus spinipenis new species are described from Argentina. We include a key to species, representative habitus illustrations for all species, character illustrations, and distribution maps for each, as well as commentary about the natural history and distributions for each species. Diagnostic characters are discussed for each species, and species relationships are hypothesized based on the analysis of internal and external morphological characters. The male of T. bidentulus (Fairmaire) is described for fi rst time. The following taxonomic changes are made: Tomarus guianucai Dechambre and Lumaret, 1985 is a new junior synonym of Tomarus rubripes (Boheman, 1858), which was formerly and incorrectly cited as occurring in Argentina.