Nannoplankton malformation during the Paleocene-Eocene Thermal Maximum and its paleoecological and paleoceanographic significance

Paleoceanography
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Abstract

The Paleocene-Eocene Thermal Maximum (PETM) is characterized by a transient group of nannoplankton, belonging to the genus Discoaster. Our investigation of expanded shelf sections provides unprecedented detail of the morphology and phylogeny of the transient Discoasterduring the PETM and their relationship with environmental change. We observe a much larger range of morphological variation than previously documented suggesting that the taxa belonged to a plexus of highly gradational morphotypes rather than individual species. We propose that the plexus represents malformed ecophenotypes of a single species that migrated to a deep photic zone refuge during the height of PETM warming and eutrophication. Anomalously, high rates of organic matter remineralization characterized these depths during the event and led to lower saturation levels, which caused malformation. The proposed mechanism explains the co-occurrence of malformed Discoaster with pristine species that grew in the upper photic zone; moreover, it illuminates why malformation is a rare phenomenon in the paleontological record.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Nannoplankton malformation during the Paleocene-Eocene Thermal Maximum and its paleoecological and paleoceanographic significance
Series title Paleoceanography
DOI 10.1002/2016PA002980
Volume 31
Issue 10
Year Published 2016
Language English
Publisher AGU
Contributing office(s) Eastern Geology and Paleoclimate Science Center
Description 17 p.
First page 1423
Last page 1439