Evolution in the Early Cretaceous planktonic foraminiferal genus Blefuscuiana

New marine data and age accuracy of the Romualdo Formation, Araripe Basin, Brazil

“…The Aptian foraminiferal association presented here has a tropical/subtropical affinity when compared with previously described associations (Sabinas Basin, Mexico 75 ; DSDP Leg 79, offshore central Morocco 76 ; Sergipe Basin, Brazil 56,77,78 ; Cassis-La Bédoule, France 36,79 ; DSDP Leg 40, Sites 363-364, Angola Basin and Walvis Ridge, offshore Angola 57,73 ; Vocontian Basin, Itália 51 ). The genera Gorbachikella, Blesfucuiana and Pseudoguembelitria have a very restricted latitudinal range, only in North Africa, Eastern Europe, Central America (including the Caribbean and Mexico) and the subtropical western North Atlantic 50,75,[80][81][82][83][84] . Biogeographic evidence suggests that these globular forms can be considered indicators of warm sea surface temperatures, the occurrence of which is related to the emergence of possibly eutrophic and/or climatic (probably hot) oceanographic conditions 83,85,86 .…”

Aptian bio-events—an integrated biostratigraphic analysis of the Almadich Formation, Inner Prebetic Domain, SE Spain

“…The Lower Aptian marine sediments globally record a major turnover in marine fauna and flora. This is mainly reflected in changes in the ammonite, belemnite, dinoflagellate, radiolarian and benthic foraminiferal taxa, radiation and diversification of planktonic foraminifera and silicoflagellates, and diversification and later crisis within the calcareous nannofossils (Caron, 1985;Williams & Bujak, 1985;Coccioni et al, 1992;McCartney, 1993;Erba, 1994;O'Dogherty, 1994;Boudagher-Fadel, 1996;Boudagher-Fadel et al, 1996, 1997aAguado et al, 1997;Bischoff & Mutterlose, 1998;Bown et al, 1998;Cecca, 1998;Mutterlose, 1998, among others). These changes coincided with other major palaeogeographic and palaeoceanographic events, such as the development of an oceanic anoxic event (Schlanger & Jenkyns, 1976;Arthur et al, 1990), widespread drowning of shallow carbonate platforms (Schlager, 1989), oceanic volcanic eruptions in the Pacific (the 'superplume episode' of Larson, 1991a), a global rise in sea level (Haq et al, 1988;Hallam, 1992) and the onset of the Cretaceous greenhouse conditions (Larson, 1991b).…”