In order to include an additional species in the genus Oristicta Tillyard, 1913, the lectotype of its sole species Oristicta filicicola Tillyard, 1913 and the holotype of Phasmosticta interposita Lieftinck, 1951, its assumed junior synonym, the original descriptions of both and numerous museum specimens identified as O. filicicola are studied and discussed. In spite of some variability being noted, it is concluded that they all are O. filicicola which is considered a monotypic species. The additional species is described as Oristicta rosendaleorum sp. nov. It is comprehensively illustrated, and its affinities are discussed. Possibly sympatric in places with O. filicicola, Oristicta rosendaleorum sp. nov. has richer black markings, lacks posterolateral processes/horns on the male’s pronotum (present in O. filicicola), and the male anal appendages are of different form. Oristicta filicicola is known from far north-eastern Queensland from Hammond Island (10.5°S) at the tip of Cape York to the Paluma Range (19°S) in the southern Wet Tropics Bioregion. Oristicta rosendaleorum sp. nov. is currently known from only two localities within 20 km of Lakeland (15.9°S) in south-eastern Cape York Peninsula.
Houston, W.W.K. & Watson, J.A.L. (1988) Odonata. In: Houston, W.W.K. (Ed.), Zoological Catalogue of Australia. Vol. 6. Australian Government Publishing Service, Canberra, pp. 33–132
Lieftinck, M.A. (1951) Results of the Archbold expeditions, no. 64. Odonata of the 1948 Archbold Cape York Expedition, with a list of the dragonflies from the Peninsula. American Museum Novitates, 1488, 1–46.
Theischinger, G. & Hawking, J.H. (2006) The Complete Field Guide to Dragonflies of Australia. CSIRO Publishing, Canberra & Melbourne, 366 pp.
Theischinger, G. & Endersby, I. (2009) Identification Guide to the Australian Odonata. Department of Environment, Climate Change & Water NSW, Sydney, 283 pp.
Tillyard, R.J. (1913) On some new and rare Australian Agrionidae (Odonata). Proceedings of the Linnean Society of New South Wales, 37/3, 403–479.
Watson, J.A.L. (1974) The distributions of the Australian dragonflies (Odonata). Journal of the Australian Entomological Society, 134, 137–149.
Watson, J.A.L. (1994) Checklist and primary taxonomic literature for Australian dragonflies. Odonatologica, 23 (1), 23–44.
Watson, J.A.L. & O’Farrell, F.A. (1991) Odonata (dragonflies and damselflies). In: CSIRO Division of Entomology (Ed.), The insects of Australia. A textbook for students and research workers. 2nd Edition. Melbourne University Press, Carlton, pp. 294–310.
Watson, T., Theischinger, G. & Abbey, H. (1991) The Australian Dragonflies. A Guide to the Identification, Distribution and Habitats of Australian Odonata. CSIRO, Canberra & Melbourne, 278 pp.