Etymology: refers to an ancient legend Quichua, from the northern limit of Argentina, about the princess Inca Uru, who by their whims and bad government was transformed by the gods into a spider and forced to endlessly work weaving.
Three new species of the monotypic genus Melloleitaoina Gerschman & Schiapelli, 1960 are described from northern Argentina: M. mutquina sp. n., M. uru sp. n. and M. yupanqui sp. n. The female specimen originally described as M. crassifemur is not conspecific with the male holotype and thus is removed
from this species and described as M. uru sp. n.; M. crassifemur is redescribed. All species are diagnosed, illustrated and a key to species is provided.