Cyrtobill darwini, a new species in a new orb-weaving spider genus from Australia (Araneae: Araneidae: Cyrtophorinae)

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – A new monotypic genus of orb-weaving spider (Araneidae) with Cyrtobill darwini as type species is described from Australia. A reduced piriform spinning field of the anterior lateral spinnerets and the construction of a horizontal, dome-shaped orb-web suggest a placement of Cyrtobill in the araneid subfamily Cyrtophorinae Simon, 1895. However, the morphology of the male pedipalp is unique within the Araneidae as the cymbium has a basal, semicircular, sclerotised rim that creates a cymbial concavity. Cyrtobill darwini are small spiders of less than 5 mm body length and occur mainly in arid habitats such as spinifex grassland in the northern half of Australia (mainly north of 30°S latitude). Adult spiders have been found all year round; however, the species seems to be predominantly winter mature. We propose new generic combinations within the Australasian Cyrtophorinae: Cyrtophora crassipes (Rainbow, 1897), comb. nov.; Cyrtophora rainbowi (Roewer, 1955), comb. nov.; Cyrtophora trigona (L. Koch, 1871), comb. nov. (all originally described from Australia); and Cyrtophora gazellae (Karsch, 1878), comb. nov. (described from Papua New Guinea). In addition, we provide an updated species list for Australian Cyrtophora Simon, 1864.