DOI: 10.5061/dryad.5p92t38g
title: Data from: Evolutionary ecology of Early Paleocene planktonic foraminifera: size, depth habitat and symbiosis

description: The carbon stable isotope (δ13C) composition of the calcitic tests of
 planktonic foraminifera has an important role as a geochemical tracer of
 ocean carbon system changes associated with the Cretaceous/Paleogene
 (K/Pg) mass extinction event and its aftermath. Questions remain, however,
 about the extent of δ13C isotopic disequilibrium effects and the impact of
 depth habitat evolution on test calcite δ13C among rapidly evolving
 Paleocene species, and the influence this has on reconstructed
 surface-to-deep ocean dissolved inorganic carbon (DIC) gradients. A
 synthesis of new and existing multispecies data, on the relationship
 between δ13C and δ18O and test size, sheds light on these issues. Results
 suggest that early Paleocene species quickly radiated into a range of
 depths habitats in a thermally stratified water column. Negative δ18O
 gradients with increasing test size in some species of Praemurica suggest
 either ontogenetic or ecotypic dependence on calcification temperature
 that may reflect depth/light controlled variability in symbiont
 photosynthetic activity. The pattern of positive δ13C test-size
 correlations allows us to (1) identify metabolic disequilibrium δ13C
 effects in small foraminifera tests, as occur in the immediate aftermath
 of the K/Pg event, (2) constrain the timing of evolution of foraminiferal
 photosymbiosis to 63.5 Ma, ∼0.9 Myr earlier than previously suggested, and
 (3) identify the apparent loss of symbiosis in a late-ranging morphotype
 of Praemurica. These findings have implications for interpreting δ13C DIC
 gradients at a resolution appropriate for incoming highly resolved K/Pg
 core records.
description: Supplementary Figure
 1Stable isotopic signals
 of multiple size fractions of 13 early Paleocene planktonic foraminifera
 species. For each time slice, plot (1) shows δ18O against test size, plot
 (2) carbon δ13C against test size and plot (3) δ13C verses δ18O, (cross
 plots are a typical method for interpreting planktonic foraminifera depth
 habitats and are therefore useful for comparison of our results with the
 wider literature). Test size is represented as the mid point in the upper
 and lower sieve size range. Genera abbreviations as follows M =
 Morozovella, Pr = Praemurica, S = Subbotina, P = Parasubbotina, E =
 Eoglobigerina, C = Chiloguembelina, G = Guembelitria, Pa =
 Parvularugoglobigerina and W = Woodringina. Grey vertical dashed lines
 indicate approximate onset of adult ecology for planktonic foraminifera
 according to Brummer et al. (1987). Time Slice D, H, I, J, K, M, P and Q
 data, this study. A to C data from D’Hondt and Zachos (1993), DSDP Site
 528 and 577 and E, G, L, N, O and R from Norris (1996), DSDP Site 384. ΔT
 = maximum interspecies δ18O offset equivalent to inferred maximum
 temperature offset; ΔM = inferred metabolic fractionation disequilibrium
 effects; ΔS = inferred photosymbiotic disequilibrium effects; ΔD =
 represents interspecies δ13C offsets. Ages are based on the ODP Leg 208
 time scale of Westerhold et al (2008). Site 528, 577 and 384 ages were
 converted by linear interpolation from Cande and Kent
 (1995).Supplementary Table
 1ODP
 Site 1262 Sample horizons and stable isotope data used in this study (M=
 Morozovella, Pr = Praemurica, S = Subbotina, P = Parasubbotina, E =
 Eoglobigerina and W = Woodringina), mcd = meters composite
 depth.