Aspects of Middle-Late Jurassic-Cretaceous Tethyan brachiopod biogeography in relation to tectonic and paleoceanographic developments

Abstract

Important tectonic and paleoceanographic events during the Middle to Late Jurassic and Cretaceous resulted in modifications to the biogeographic distributions of Tethyan brachiopod genera from Europe. The development of the Central Atlantic Ocean during the Jurassic-Early Cretaceous led to an increase in the number of brachiopod genera common to both the Mexico/Eastern Pacific and Northwestern Europe/Tethyan regions. Brachiopod genera recorded from Tethys in Europe show evidence of migration via at least four major routes as a consequence of tectonic developments (dates in parentheses indicate stages where evidence exists for generic links): (1) Northwestern Europe via Mexico/Caribbean region (Oxfordian) to South America (Valanginian, Hauterivian, Cenomanian); (2) Eastern Tethys via Eastern Africa (East African Seaway) to the South Atlantic Ocean (Late Turonian-Early Coniacian, Santonian-Campanian); (3) Northwestern Europe via the Central Atlantic to the opening South Atlantic, reaching the Antarctic Peninsula region (late Albian, Santonian, Campanian); (4) Europe northward to higher latitudes (Russian Platform to Barents Sea, Berriasian-Valanginian; Europe to East Greenland, Valanginian; Europe-Canadian Arctic Islands, Albian and also earlier during the Jurassic). For routes (1)–(3) direction of dispersal may prove to have been in either direction, at times it appears to have been in a southerly direction for route (3). Stratigraphic age relationships suggest a south to north dispersal for routes considered under (4) (except for the link to the Canadian Arctic Islands, which is inconclusive). By the Late Cretaceous the low-latitude faunas of Europe and America had become isolated by the increasing width of the Central Atlantic Ocean although some genera appear to be cosmopolitan.