The fossil record, apparent age, distributions, and putative mechanisms of vicariance are explored for various groups of terrestrial arthropods. Examined in particular are Cretaceous (145-65 mya) fossil records and continental drift, and the classic distribution of disjunction among temperate regions of the southern land masses (Australia, New Zealand, Chile and Argentina, and southern Africa), the "Austral Region." Many arthropod groups have fossil records that extend to the Cretaceous, or even earlier into the Mesozoic, indicating the possibility that drifting continents had pervasive effects on distributions of extant taxa. Some groups, however, radiated in the Tertiary, and thus were not affected by drifting continents, such as the schizophoran Diptera, ditrysian Lepidoptera, "higher" termites (Termitidae and Rhinotermitidae), and many aculeate Hymenoptera and phytophagan Coleoptera. Interestingly, many species in these young groups show little or no austral disjunctions. Fossil evidence also reveals, however, that the view of austral disjunctions as remnants of continental drift is simplistic and naïve. Many disjunct austral arthopods, in fact, have fossils in the northern (largely Laurasian) continents, indicating formerly widespread distributions. Also, Pleistocene fossils indicate dramatic changes in the distributions of many extant species. These observations have significant implications for vicariance biogeography and suggest an important but ignored role of dispersal and climate on distributions.
Keywords: Fossils biogeography
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA