| abstract | The oribatid mite genus Zachvatkinibates, found in littoral, forest canopy, and forest litter habitats, includes some species showing distinct sexual dimorphism in the octotaxic system of dermal glands, and others lacking this dimorphism. Three new species in this genus are described on the basis of adults, each of which shows species-specific sexual dimorphism: Z. nortoni sp. nov. and Z. schatzi sp. nov. from beach debris in British Columbia, Canada, and Z. shaldybinae sp. nov. from the littoral in eastern and northeastern Canada. We discuss the association of sexual dimorphism with the littoral habitat of species in this genus and, more generally, the expression of sexually dimorphic porose areas in Ceratozetoidea. We revise the diagnosis for the genus Zachvatkinibates and present a revised key for adults of Zachvatkinibates species of North America north of Mexico. |