JURASSIC BELEMNITE DISTRIBUTION PATTERNS - IMPLICATIONS OF NEW DATA FROM ANTARCTICA AND ARGENTINA

Belemnites are nektopelagic cephalopods which developed a widespread p attern of distribution in the Jurassic, and most authors have accepted that their centre of origin was Europe. Available data suggest that t he belemnites developed a global distribution only in the Toarcian, so me 15 Ma after their first appearence in the European Hettangian. Deve lopment of the Boreal and Tethyan belemnite realms took place in the M iddle Jurassic and continued through to the Cretaceous. New data from Argentina and the Antarctic Peninsula reaffirms the development of the global distribution of belemnites in the Toarcian, and sheds new ligh t on the biogeographical patterns for the Jurassic of the southern hem isphere. This has considerable implications for understanding the deve lopment of faunal realms in the Mesozoic.