Research Assistant Cleveland Museum of Natural History Cleveland Heights, Ohio
Australia is among the most biodiverse countries in the world. Up to 10% of the world’s plants and animals are Australian, yet an estimated 50% of species remain undescribed on the continent. Australia’s native dung beetles account for about 7.5% of the worldwide diversity of scarabaeines. Among dung beetle genera, the cosmopolitan Onthophagus is the most diverse lineage, representing over 2,300 described species worldwide. There are currently 203 described Onthophagus species in Australia, but the group is underworked and in great need of focused study as cryptic species likely represent a substantial fraction of the continent’s biodiversity. Eric Matthews, tasked with reviewing Australian scarabaeines in the 1970’s, provided a legacy for understanding the biodiversity of Australia’s dung beetle fauna. In his revision of Australian Onthophagus, Matthews defined 24 species groups in which 165 species were organized. Although these groupings were never intended to be natural, all subsequent reviews of the genus have followed Mathews’ organization. Based on preliminary CO1 data, many of Matthews’ groupings are supported; however, several groups require deeper study. Here, we review the Matthews’ species group, IX. Australis. We use niche modeling to predict potential suitable habitat and identify environmental factors associated with the distribution of Mesomerodon species. We characterize the group, provide spatial and temporal distributions, and discuss distributions of the species in relation to Australian landscape.