A new monotypic genus, Mainosa, is described to accommodate the Australian ‘shuttlecock wolf spider’, Mainosa longipes (L. Koch 1878) (= Lycosa mainae McKay 1979, new synonymy) as the type species. The male of this species is described for the first time. Mainosa longipes differs from other wolf spiders in having a the distinct color pattern of the abdomen, with white transverse bars and lines on a dark surface, and unusually long legs in males. Its genital morphology confirms M. longipes as a member of the subfamily Lycosinae. Mainosa longipes inhabits areas in South Australia and Western Australia with dry sandy soils in Acacia litter, where it constructs palisades around the entrance of its burrow. It appears to reproduce in winter.