%0 Journal Article
%A Caus Gracia, Esmeralda
%A Bernaus, J.M.
%A Calonge, Amelia
%A Martín Chivelet, Javier
%T Mid-Cenomanian separation of Atlantic and Tethyan domains in Iberia by aland-bridge: The origin of larger foraminifera provinces?
%D 2009
%@ 0031-0182
%U https://hdl.handle.net/20.500.14352/50469
%X The Middle and Late Cretaceous shallow-water carbonate platforms widely exposed across the eastern halfof the Iberian Peninsula including the Betic Cordillera, the Iberian Ranges and the Pyrenees provides anexcellent material for analyzing the origin of two Iberian Late Cretaceous larger foraminifera provinces, theBetic and the Pyrenean: the former corresponds to the Tethyan domain, the latter to the Atlantic domain. Thespatiotemporal distribution in the three studied areas of the larger foraminifera k-strategists, theAlveolinaceans, from the latest Albian–Cenomanian time interval suggests that separation of the two faunalprovinces started during Early Cenomanian (mid-Cretaceous Global Community Maturation cycle), and theshelves of the Iberian seaway formed the boundaries of the corresponding bioprovinces. This occurred beforethe Betic–Pyrenean communication near the Middle–Late Cenomanian transition was interrupted by a landbridge.Therefore, the separation of the two bioprovinces cannot be due to the physical barrier created by theopening or closure of the shallow seaway across the Iberia: here it is attributed to the differences in theecological gradients. At the end of the Cenomanian, the Cenomanian–Turonian eutrophication eventeliminated all the k-strategist larger foraminifera to such a degree that all their essential k-strategyinformation was lost. The newly arising k-strategist foraminifera needed a considerable time (8–10 m.y.) torecover their lost genetic complexity: this occurred during the Coniacian in the following GCM cycle.
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