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 The geographical divisions are taken from the "Getty Thesaurus of Geographical Names"




Duda & Kohn, 2005, p. 265:

  • "While the East Pacific Barrier has likely thwarted dispersal between the central and eastern Pacific since the early Cenozoic (Grigg and Hey, 1992), the broad Tethyan connection between the Atlantic and Indian Oceans persisted until the Middle Miocene (Harzhauser et al., 2002; Vrielynck et al., 1997). Moreover, the Benguela cold current and upwelling system around the southwestern tip of Africa, that currently limits migration of tropical marine organisms between the eastern Atlantic and Indian Oceans, did not originate until the Miocene (Diester-Haass and Schrader, 1979; Meyers et al., 1983; Siesser, 1980) and did not intensify until the Upper Pliocene (Meyers et al., 1983; Shannon, 1985). Also, because of the continued widening of the Atlantic during the Cenozoic (Adams, 1981), the Mid-Atlantic Barrier was presumably somewhat weaker in the Eocene and Oligocene than today. Hence, although the East Pacific Barrier likely explains the break between the central and eastern Pacific, the location or means of the Atlantic-Indian Ocean barrier is ambiguous. Analyses of Caribbean fossil reef corals and squids suggest that the Mid-Atlantic Barrier did cause western and eastern Atlantic taxa to diverge. Origination rates of coral taxa in the western Atlantic decreased during the Cenozoic due to declining migration of corals from the Mediterranean, and the western Atlantic coral fauna differentiated from the eastern Atlantic fauna by the Lower Miocene (Budd, 2000). Anderson (2000) attributes the separation of ancestral lineages of Loligo and Sepioteuthis squids between the EP+WA and the EA+IP to the widening of the Atlantic during the Cretaceous. On the contrary, histories of Oligocene divergence of other marine taxa across the Tethys Realm suggest that the geographic break that delimited ancestral Conus lineages may have occurred between the eastern Atlantic and western Indian Oceans and not in the Mid-Atlantic. Eels of the genus Anguilla and killifish of the genus Aphanius separated into western and eastern Tethyan counterparts between 30 and 45mya (Hrbek and Meyer, 2003; Tsukamoto and Aoyama, 1998); these dates well precede the final closure of the Tethyan seaway and are strikingly similar to the estimated date of divergence for the two main Conus clades between 33 and 55mya. Furthermore, disparity between the gastropod faunas of the western and eastern reaches of the Tethys Realm increased dramatically between Oligocene and Lower Miocene (Harzhauser et al., 2002). This was sufficient for these authors to propose the origin of two biogeographic provinces within this region during the Oligocene: the Mediterranean-Iranian Province in the western Tethys Realm and the western Indian–eastern African Province in the eastern Tethys Realm. Thus, concordance in dates of divergence across the Tethys Realm among several marine taxa suggests a geographic break situated between the eastern Atlantic and western Indian Oceans rather than at the Mid-Atlantic."


  • Adams, C.G., 1981. An outline of Tertiary palaeogeography. In: Cocks, L.R.M. (Ed.), The Evolving Earth. British Museum of Natural History, London, pp. 221–235.
  • Anderson, F.E., 2000. Phylogeny and historical biogeography of the Loliginid squids (Mollusca: Cephalopoda) based on mitochondrial DNA sequence data. Mol. Phylogenet. Evol. 15, 191–214.
  • Budd, A.F., 2000. Diversity and extinction in the Cenozoic history of Caribbean reefs (Invited review). Coral Reefs 19, 25–35.
  • Diester-Haass, L., Schrader, H.J., 1979. Neogene coastal up-welling history oV northwest and southwest Africa. Mar. Geol. 29, 39–53.
  • Thomas F. Duda Jr. & Alan J. Kohn, 2005. Species-level phylogeography and evolutionary history of the hyperdiverse marine gastropod genus Conus; Molecular Phylogenetics and Evolution 34 (2005) 257–272.
  • Harzhauser, M., Piller, W.E., Steininger, F.F., 2002. Circum-Mediterranean Oligo-Miocene biogeographic evolution—the gastropods’ point of view. Palaeogeogr. Palaeoclimatol. Palaeoecol. 183, 103–133.
  • Hrbek, T., Meyer, A., 2003. Closing of the Tethys Sea and the phylogeny of Eurasian killiWshes (Cyprinodontiformes: Cyprinodontidae). J. Evol. Biol. 16, 17–36.
  • Meyers, P.A., Brassell, S.C., Huc, A.Y., Barron, E.J., Boyece, R.E., Dean, W.E., Hay, W.W., Keating, B.H., McNulty, C.L., Nohara, M., Schallreuter, R.E., Sibuet, J.-C., Steinmetx, J.C., Stow, D., Stadner, H., 1983. Organic geochemistry of sediments recovered by DSDP/IPOD leg 75 from under the Benguela Current. In: Thiede, J., Suess, E. (Eds.), Coastal Up-Welling: its Sedimentary Record. Part B. Sedimentary Records of Ancient Coastal Upwelling. Plenum Press, New York, pp. 453–466.
  • Shannon, L.V., 1985. The Benguela ecosystem. Part I. Evolution of the Benguela physical features and processes. Oceanogr. Mar. Bio. Annu. Rev. 23, 105–182.
  • Siesser, W.G., 1980. Late Miocene origin of the Benguela upwelling system oV northern Namibia. Science 208, 283–285.
  • Tsukamoto, K., Aoyama, J., 1998. Evolution of freshwater eels of the genus Anguilla: a probable scenario. Environ. Biol. Fishes 52, 139–148.
  • Vrielynck, B., Odin, G.S., Dercourt, J., 1997. Miocene palaeogeography of the Tethys Ocean: potential global correlations in the Mediterranean. In: Montanari, A., Odin, G.S., Coccioni, R. (Eds.), Miocene Stratigraphy: An Integrated Approach. Elsevier, Amsterdam, pp. 157–165.

old divisions

Geographic divisions


  • Arctic Ocean
  • Atlantic Ocean
  • Indian Ocean
  • Pacific Ocean
  • Southern Ocean
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