How localized are the distributions of Australian scarabs (Coleoptera, Scarabaeoidea)?

The degree of localization in the distribution of Australian scarabaeine (320 spp.), aphodiine (160 spp.), geotrupid (166 spp.) and dynastine (182 spp.) scarabs is analysed. Localization differs among these groups, appearing to increase marginally from the Dynastinae, to the Aphodiinae, to the Scarabaeinae, to the Geotrupidae, but with significant differences within groups, e.g. the scarabaeine tribes Onthophagini and Scarabaeini. However, the Australian fauna lacks the high proportion of widespread species characteristic of the West Palaearctic Scarabaeinae, Aphodiinae and Geotrupidae. This difference reflects the different ecological histories of the two regions.