Fusiform and laterally compressed alveolinaceans (Foraminiferida) from both sides of the Late Cretaceous Atlantic
Vicedo, Vicent; Aguilar, Marcelo; Caus, Esmeralda; Hottinger, Lukas
published: Aug 1, 2009
ArtNo. ESP155025302003, Price: 29.00 €
Shallow, restricted carbonate facies in the Late Cretaceous yield on both sides of the Atlantic axially compressed, discoidal, and axially elongate, fusiform alveolinacean shells. Their structural analysis reveals that the taxa involved are dissimilar on both sides of the Atlantic. The structural differences warrant separate generic names for the alveolinacean associations on either side of the Atlantic. Two of them, Fabalveolina and Caribalveolina, are new. An important element of distinction is found in the endoskeleton: solid basal layers, that constitute the median zone of the discs and the columellas of the fusiform shells, may be pierced by tubular supplemental passages or the same shell elements may be constructed by septula and floors delimiting more regular stacks of chamberlets in supplemental layers. Fusiform alveolinaceans are restricted to two realms on the shores of the Atlantic, the Caribbean in the West and the Pyrenean Gulf in the East. Compressed alveolinaceans characterize the Caribbean on one hand, the Western Neotethys on the other. They seem to be absent from the Pyrenean Gulf, where they might be substituted by the Meandropsinidae. This emphasises the importance of the Pyrenean Gulf as separate faunal province.