ABSTRACT
— Since most, if not all, the spider species of the Florida peninsula are relatively recent arrivals, either because the land had been fully submerged at some time during the Pleistocene or because that islands’ areas in the Florida archipelago during interglacial periods were small and local extinctions of the fauna were likely, an analysis of present-day distributions permits determination of the sources of the spider fauna. Dispersal during the Pleistocene played the dominant role in the origin of the peninsular Florida fauna. Climatic constraints to present distributions offer additional clues to origins. By using explicit criteria, most species can be placed in one of four origin groups: northern (far and near), western, southern (Caribbean), and autochthonous (originating on the islands of the Florida “archipelago”). In addition some spiders are just “neotropical,” either arriving along the Gulf Coast or through the West Indies, and others are cosmopolitan with recent anthropogenic factors likely responsible. This combination of historic contingency and ecological limitations make the spider fauna of Florida both diverse and somewhat limited. The contribution of the Greater Antilles to the spider fauna of Florida is relatively small, amounting to less than 10%.
