The ecological biogeography of onychophorans has been the subject of some qualitative observations, but the resultshave been inconsistent. This paper presents the results of (1) statistical analyses of 172 geographic quadrats for both onychophoranfamilies (worldwide) and (2) independent graphic analyses of most South African and Australian species. Both types of analysis produced different results, including a correlation of occurrence with Pleistocene vegetation, which does not,—..imply causation. Although altitude and rainfall correlate with the distribution of some South African and Australian taxa, each of the following factors failed to explain by itself the barriers that limit onychophoran distribution at the global level; mean annualrainfall and temperature, photosynthesis, and types of climate, vegetation and biome. The barriers seem to be a product of severalecological factors which depend on the onychophoran taxon.
