A phylogenetic analysis of Oniticellini and Onthophagini based on 136 morphological characters supports the hypothesis that the oniticellini is paraphyletic without the onthophagini. Only one of the three currently recognised Oniticellini subtribes, the Helictopleurina, is monophyletic and it should be recognised as a distinct tribe. The two remaining subtribes should be redefined with the placement of Paroniticellus and Liatongus monstrosus in one and the remaining genera placed in a second. The genus Liatongus is not monophyletic and there is support for the creation of two new genera based on the three North American species. Within the onthophagines, the genus Onthophagus also appears as paraphyletic. Ancestral oniticellines and onthophagines were coprophagous with alternative food sources and biologies evolving later in younger lineages. Myrmecophily/termitophily is also derived and may have only evolved once in the speciose onthophagine tribe. This phylogeny supports an early age for the split of the Madagascar helictopleurines from the lineage leading to the remaining oniticellines and onthophagines.