EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

A way-out from the maze of middle Miocene Sphaeroidinellopsis (planktonic foraminifera)

Alessio Fabbrini1, Ilaria Zaminiga1, Thomas Ezard2, and Bridget Wade1
Alessio Fabbrini et al.
  • 1Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom
  • 2Ocean and Earth Science, University of Southampton, Waterfront Campus, National Oceanography Centre, Southampton, SO14 3ZH, United Kingdom

The taxonomy and phylogeny of the Miocene to Recent genus Sphaeroidinellopsis have been documented in previous studies, but the evolution of this lineage remains unclear. Some authors debated this genus in the past, choosing a variety of parameters to discriminate between morphospecies. Here we present new high detail analyses of specimens from Ocean Drilling Program (ODP) Site 925 (Ceara Rise, western equatorial Atlantic) and ODP Site 959 (Deep Ivorian Basin, eastern equatorial Atlantic). We present transitional individuals Sphaeroidinellopsis disjuncta–Sphaeroidinellopsis kochi, a speciation event never described before. These transitional specimens are characterized by extreme morphological features such as elongated and sac-like final chambers, requiring amendments to the current classification and taxonomy of these morphospecies. An alternative hypothesis is presented to assess these new observations within the evolutionary mosaic of Sphaeroidinellopsis.

How to cite: Fabbrini, A., Zaminiga, I., Ezard, T., and Wade, B.: A way-out from the maze of middle Miocene Sphaeroidinellopsis (planktonic foraminifera), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11783,, 2022.


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