A74. Packer. L. 2005. A new species of Geodiscelis (Hymenoptera: Colletidae: Xeromelissinae) from the Atacama Desert of Chile. Journal of Hymenoptera Research. 14:84-91.
Abstract: Geodiscelis longiceps Packer, new species, is described from northern Chile. Morphologically, it is somewhat intermediate between Chilimelissa and Geodiscelis, but is clearly more closely related to the latter as indicated by numerous synapomorphies such as the broad basal bands of appressed tomentum, long and thin hind tibial spurs, well developed mesotarsal setae in the female, large and well sclerotised proctiger, angulate mesal margin and elongate inner membranous process to the gonocoxites and absence of a ventroapical process to the gonobase. It differs from the type species of the genus in the enormously elongate head and mouthparts but otherwise normal glossa. Based upon character states shared by the new species and the type species of the genus, a revised diagnosis for Geodiscelis is provided. Some comments on the adaptive significance of extremely elongate heads in the Xeromelissinae are made.