AbstractThe new genus Arborilispinus from the Neotropical region is described. Although further undescribed species of this genus exist in South America, only two species, A. longulus and A. mirabilis, are here described based on male specimens from the Brazilian and Peruvian Amazon rainforest. According to the tarsal formula 4,4,4, Arborilispinus should be placed in the subtribe Glyptomina of the tribe Thoracophorini. A morphology-based cladistic analysis, however, contradicts the existing classification of Thoracophorini into subtribes. Alternative systematic relationships among the Neotropical genera of Glyptomina and Thoracophorina suggested by the cladistic analysis are discussed.