RESUMO
The Palaearctic species of Aphodius Hellwig, 1798, subgenus Liothorax Motschulsky, 1860 are revised using a combination of chromosome analysis, molecular phylogenetics and morphological statistical analysis. Sixteen species are recognised, one of which is shown to comprise two subspecies. Based mainly on the morphology of the aedeagal endophallus and the phylogenetic analysis, they are placed in two groups: the. niger group, apparently monophyletic, comprising Aphodius (Liothorax) niger Illiger, 1798, A. (L.) muscorum (Ádám, 1994), stat. rest., A. (L.) felixsp. nov., A. (L.) bellumgerenssp. nov., A. (L.) bameulisp. nov., A. (L.) krellisp. nov., A. (L.) isikdagensis (Balthasar, 1953), A. (L.) albertisp. nov. and A. (L.) wilsonae Maté et Angus, 2005, stat. rest.; and the plagiatus group, almost certainly paraphyletic, comprising A. (L.) plagiatus (Linnaeus, 1767), including A. (L.) p. plagiatus and A. (L.) p. sinoplagiatussubsp. nov., A. (L.) rodrigoisp. nov., A. (L.) discoidesA. Schmidt, 1916, stat. rest., A. (L.) rutilipennis (Baudi di Selve, 1870), stat. rest., A. (L.) chellalasp. nov., A. (L.) kraatzi Harold, 1868, and A. (L.) rusakovi Gusakov, 2004. A key to the species is given as well as details of their morphology, distributions, and habitats.