It is an important taxonomic work by Rita Marchisio (prematurely dead on January 2011) and by prof. Mario Zunino of the University of Urbino. The work (in italian and english abstract) is a critical analysis of the systematics of the genus Copris Müller 1764, a group of Scarabaeidae (Coleoptera) distributed in Africa, Eurasia and in both North and Central America. In the work the genus Copris is redefined, considering Microcopris as a taxon of subgenus rank, while Paracopris, Litocopris and Pseudopedaria are considered synonyms of Copris s. str. Pseudocopris is also considered, albeit with some reserve, as a synonym of Copris s. str. Then, the different afrotropical groups (hispanus, laioides, orion, mesacanthus, typhoeus, diversus, sinon), american groups (lugubris, armatus, rebouchei) and Oriental Regions and Paleartic groups  (sacontala, lunaris) are discussed. For two Afro-tropical species, a new genus Afrontherus is preliminarily proposed. The last part of the work formulates a few hypotheses regarding the phylogenetic relations of the genus Copris and of the identified groups within it.