Mark Cooper School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa Arthropods ISSN 2224-4255 http://www.iaees.org/publications/journals/arthropods/online-version.asp 2020 9 3 104 111 International Academy of Ecology and Environmental Sciences Hong Kong 123 February 2020 30 March 2020 1 September 2020 diversity gradient latitude richness species The Tropical Conservativism Hypothesis suggests processes of speciation, extinction and dispersal resulted in higher species richness at the tropics and declined away from the equator. Biogeographical Conservativism Hypothesis suggests that the processes invoked are not intrinsic to the tropics but were dependent on historical biogeography to determine the distribution of species richness. 77 valid species were identified as belonging to the genus Gnomeskelus in order to test between the two hypotheses. There was a significant correlation between the number of species and latitudinal degrees away from the equator (r=-0.7145, r2=0.5105, n=77, p less than 0.00001). Alternatively, there may be an evolutionary preference for temperate environments appearing to have led to climatic constraints on dispersal based primarily on temperature seasonality gradients. http://www.iaees.org/publications/journals/arthropods/articles/2020-9(3)/latitudinal-gradient-in-Gnomeskelus-species-richness.pdf