Depth-habitat reorganization of planktonic Foraminifera across the Albian/Cenomanian boundary

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doi: 10.1666/09027.1
Author(s): Ando, Atsushi; Huber, Brian T.; MacLeod, Kenneth G.
Author Affiliation(s): Primary:
Smithsonian Institution, National Museum of Natural History, Department of Paleobiology, Washington, DC, United States
Other:
University of Missouri-Columbia, United States
Volume Title: Paleobiology
Source: Paleobiology, 36(3), p.357-373. Publisher: Paleontological Society, Lawrence, KS, United States. ISSN: 0094-8373 CODEN: PALBBM
Note: In English. Includes appendix. 75 refs.; illus., incl. sketch map
Summary: New mid-Cretaceous stable isotope (δ18O and δ13C) records of multiple planktonic foraminiferal species and coexisting coccoliths from Blake Nose (western North Atlantic) document a major depth-ecology reorganization of planktonic foraminifera. Across the Albian/Cenomanian boundary, deep-dwelling Praeglobotruncana stephani and Rotalipora globotruncanoides adapted to living at a shallower depth, while, at the same time, the population of surface-dwelling Paracostellagerina libyca declined. Subsequently, the opportunistic species Hedbergella delrioensis shifted to a deep environment, and the deep-dwelling forms Rotalipora montsalvensis and Rotalipora reicheli first appeared. The primary paleoenvironmental cause of the observed changes in planktonic adaptive strategies is uncertain, yet their coincidence with an earliest Cenomanian cooling trend reported elsewhere implicates the importance of reduced upper-ocean stratification. Although there has been an implicit assumption that the species-specific depth habitats of fossil planktonic foraminifera were invariant through time, planktonic paleoecology is a potential variable. Accordingly, the possibility of evolutionary changes in planktonic foraminiferal depth ecology should be a primary consideration (along with other environmental parameters) in paleoceanographic interpretations of foraminiferal stable isotope data.
Year of Publication: 2010
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Albian; Atlantic Ocean; Biostratigraphy; Blake Nose; Blake Plateau; C-13/C-12; Carbon; Cenomanian; Cretaceous; Diagenesis; Foraminifera; Habitat; Invertebrata; Isotope ratios; Isotopes; Leg 171B; Lower Cenomanian; Lower Cretaceous; Marine environment; Mesozoic; Microfossils; North Atlantic; O-18/O-16; ODP Site 1050; Ocean Drilling Program; Oxygen; Paleo-oceanography; Paleoecology; Paleoenvironment; Planktonic taxa; Protista; SEM data; Stable isotopes; Stratigraphic boundary; Upper Albian; Upper Cretaceous
Coordinates: N300600 N300600 W0761406 W0761406
Record ID: 2010068310
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