Échanges et colonisations fauniques (Ammonitina) entre Téthys et Atlantique sud au Crétacé supérieur : voies atlantiques ou sahariennes ? (Late Cretaceous faunal exchange and colonization (Ammonitina) between the Tethys and the South Atlantic: Atlantic or Saharan routes?)

摘要: Mots-Clefs : Paleogeographie ; Tethys Atlantique du Sud Cretace superieur Ammonites Abstract: During the Late Cretaceous, generally considered as a warm period, area covered by seas reached maximum. The transgressive optima of Cenomanian and Early Turonian induce creation new domains epicontinental sea in Saharan regions (Trans-Saharan Seaway). this period ammonite faunas are remarkably homogenous between 60°N 60°S. Originating from these stocks cosmopolite ammonites, which, however, very largely adapted to open distal platform environments, some groups individualized capable colonizing regions. These endemic have convergent morphologies. Migration routes north (from southern margins Tethys) or south (starting eastern South Atlantic, via Benue Trough) may simultaneously channeled colonization Trans-Saharan Sea.