Abstract

Globorotalia inconspicua Howe, G. aculeata Jenkins, G. Perclara Loeblich and Tappan (senior synonym of G. reissi Loeblich and Tappan), Globigerina pauciloculata Jenkins, and Candeina antarctica Leckie and Webb are Cenozoic species interpreted to have been adapted to a planktic habitat. Their restriction, however, to shallow marine or marginal marine paleoenvironments suggests that they were benthic species. These taxa are associated with reduced planktic foraminiferal diversity, a low P/B (planktic/benthic) ratio, and an inner shelf benthic foraminiferal biofacies. A new genus, Praepararotalia, is erected for several species interpreted to be phylogenetically related to the benthic genus Pararotalia. Praepararotalia cretacea (new species), which is described from the Maastrichtian Navesink Formation in New Jersey, gave rise to the early Paleocene species Praepararotalia perclara. In addition, stable isotopic (delta 18 O and delta 13 C) signatures of all praepararotaliid species in this study cluster closer to benthic foraminiferal signatures and are distinct from normal marine planktic taxa from the Cretaceous and the Paleocene. A benthic paleohabitat is suggested for the Danian species Antarcticella pauciloculata (Jenkins) because of its dominant occurrence in shallow facies of marginal basins in the southern high latitudes. The species may be phylogenetically linked to P. cretacea n. sp. and is apparently the stem taxon of a Southern Ocean Paleogene evolutionary lineage that includes A. cecionii (Canon and Ernst), A. zeocenica (Hornibrook and Jenkins), and A. antarctica (Leckie and Webb).

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