Late Cretaceous alveolinaceans (larger foraminifera) of the Caribbean palaeobioprovince and their stratigraphic distribution

Abstract

Architectural analysis of the Late Cretaceous alveolinaceans of the Caribbean palaeobioprovince has made it possible to separate four genera: Praechubbina, Chubbinella gen. nov., Chubbina and Caribalveolina. The first three genera belong to the family Rhapydioninidae, while the fourth is placed in the family Alveolinidae. Two species, Praechubbina breviclaustra and P. oxchucensis sp. nov., represent the primitive genus Praechubbina, while the species cardenasensis and obesa, previously ascribed to this genus, must be reassigned respectively to Chubbinella gen. nov. and Caribalveolina. The species Chubbina jamaicensis, C. macgillavryi and C. fourcadei sp. nov. complete the inventory of Chubbina. The alveolinid genus Caribalveolina comprises two species, C. obesa and C. michaudi. Caribbean alveolinaceans include two successive assemblages. The lower assemblage is characterized by Praechubbina oxchucensis, P. brevisclaustra, Chubbinella cardenasensis and Caribalveolina obesa. The upper assemblage is represented by the genus Chubbina, with C. fourcadei, C. jamaicensis and C. macgillavryi, and Caribalveolina michaudi. The age of the lower assemblage is uncertain (probably Late Campanian–Early Maastrichtian), while the upper assemblage has been dated by strontium isotope stratigraphy as Late Maastrichtian.

http://zoobank.org/urn:lsid:zoobank.org:pub:88A5CA4D-3D6F-42E9-BEE8-EF3F7B3BA85F

Keywords:

• alveolinaceans
• larger foraminifera
• shell-architecture
• Caribbean
• biostratigraphy
• Sr-isotope stratigraphy

Acknowledgements

Sincere thanks go to Prof. Lukas Hottinger for his very useful suggestions and for sharing his knowledge of larger foraminifera. The financial support of the Spanish Ministry of Education and Science (project CGL2006–02899) and the Spanish Ministry of Science and Innovation (project CGL2009–08371) is gratefully acknowledged.

Notes

^§Numerical age from McArthur et al. (2001, look-up table version 4: 08/04) calculated by combining the statistical uncertainty of the mean of the isotopic values with the uncertainty of the seawater curve.

^#No favoured age or lower age limit can be derived from the look-up table for Sr-isotopic values close to the maximum Late Cretaceous ratio near the K/T boundary.