Size-related stable isotope changes in Late Cretaceous and Recent planktic foraminifera from the western tropical Atlantic, supplement to: Bornemann, André; Norris, Richard D (2007): Size-related stable isotope changes in Late Cretaceous planktic foraminifera: Implications for paleoecology and photosymbiosis. Marine Micropaleontology, 65(1-2), 32-42


The paleoecology of Cretaceous planktic foraminifera during the Late Cenomanian to Coniacian period (~95-86 Ma) remains controversial since much of the tropical marine record is preserved as chalk and limestone with uncertain geochemical overprints. Here we present delta13C and delta18O data from sieve size fractions of monospecific samples of exceptionally well preserved planktic foraminifera recovered during Ocean Drilling Program Leg 207 (Demerara Rise, western tropical Atlantic). Our results suggest that all species studied (Hedbergella delrioensis, Heterohelix globulosa, Marginotruncana sinuosa, Whiteinella baltica) grew primarily in surface waters and did not change their depth habitat substantially during their life cycle. Comparison of size-related ontogenetic trends in delta13C in Cretaceous and modern foraminifera further suggests that detection of dinoflagellate photosymbiosis using delta13C is confounded by physiological effects during the early stages of foraminifer growth, raising doubts about previous interpretations of photosymbiosis in small foraminifera species. We propose that obligate photosymbiosis involving dinoflagellates may not have evolved until the Campanian or Maastrichtian since our survey of Cenomanian-Coniacian species does not find the delta18O and delta13C size-related trends observed in modern foraminifer-dinoflagellate symbioses.

Related Identifier
Metadata Access
Creator Bornemann, André; Norris, Richard D
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2007
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 4 datasets
Discipline Earth System Research
Spatial Coverage (-78.000W, 2.500S, -45.000E, 27.000N); North Atlantic Ocean; Little Bahama Bank; Ceara Rise
Temporal Coverage Begin 2003-01-15T00:00:00Z
Temporal Coverage End 2003-02-16T00:00:00Z