The impact of Cenozoic cooling on assemblage diversity in planktonic foraminifera

Research output: Contribution to journalArticle

Authors

  • Isabel Fenton
  • Paul Pearson
  • A Farnsworth
  • DJ Lunt
  • Paul Markwick
  • Andy Purvis

Colleges, School and Institutes

Abstract

The Cenozoic planktonic foraminifera (PF) (calcareous zooplankton) have arguably the most detailed fossil record of any group. The quality of this record allows models of environmental controls on macroecology, developed for Recent assemblages, to be tested on intervals with profoundly different cli- matic conditions. These analyses shed light on the role of long-term global cooling in establishing the modern latitudinal diversity gradient (LDG)— one of the most powerful generalizations in biogeography and macroecology. Here, we test the transferability of environment-diversity models developed for modern PF assemblages to the Eocene epoch (approx. 56–34Ma), a time of pronounced global warmth. Environmental variables from global cli- mate models are combined with Recent environment–diversity models to predict Eocene richness gradients, which are then compared with observed patterns. The results indicate the modern LDG—lower richness towards the poles—developed through the Eocene. Three possible causes are suggested for the mismatch between statistical model predictions and data in the Early Eocene: the environmental estimates are inaccurate, the statistical model misses a relevant variable, or the intercorrelations among facets of diversity— e.g. richness, evenness, functional diversity—have changed over geological time. By the Late Eocene, environment–diversity relationships were much more similar to those found today.

Details

Original languageEnglish
Article number20150224
JournalPhilosophical Transactions of the Royal Society of London Series B
Volume371
Issue number1691
Early online date14 Mar 2016
Publication statusPublished - 5 Apr 2016

Keywords

  • planktonic foraminifera, Eocene, latitudinal diversity gradient, global climate model