Global shifts in Noelaerhabdaceae assemblages during the late Oligocene-early Miocene

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doi: 10.1016/j.marmicro.2013.07.004
Author(s): Plancq, Julien; Mattioli, Emanuela; Henderiks, Jorijntje; Grossi, Vincent
Author Affiliation(s): Primary:
Université Lyon I, Laboratoire de Géologie de Lyon, Villeurbanne, France
Uppsala University, Sweden
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, Vol.103, p.40-50. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. Includes appendix. 93 refs.; illus., incl. 1 plate, sketch map
Summary: This study investigates abundance variations in Noelaerhabdaceae assemblages during the late Oligocene-early Miocene at three subtropical sites in the Atlantic and Pacific oceans (DSDP Sites 516, 608 and 588). At these three sites, nannofossil assemblages were characterized by the successive high proportion of Cyclicargolithus, Dictyococcites and Reticulofenestra. Local paleoceanographic changes, such as the input of nutrient-poor water masses, might explain shifts in ecological prominence within the Noelaerhabdaceae at DSDP Site 516 (South Atlantic). But the similar timing of a decline in Cyclicargolithus at the three studied sites more likely corresponds to a global process. Here, we explore possible causes for this long-term taxonomic turnover. A global change in climate, associated with early Miocene glaciations, could have triggered a decline in fitness of the taxon Cyclicargolithus. The ecological niche made vacant because of the decrease in Cyclicargolithus could then have been exploited by Dictyococcites and Reticulofenestra that became prominent in the assemblages after 20.5 Ma. Alternatively, this global turnover might reflect a gradual evolutionary succession and be the result of other selection pressures, such as increased competition between Cyclicargolithus and Dictyococcites/Reticulofenestra. A diversification within Dictyococcites/Reticulofenestra, indicated by an expansion in the size variation within this group since ∼20.5 Ma, may have contributed to the decreased fitness of Cyclicargolithus. Abstract Copyright (2013) Elsevier, B.V.
Year of Publication: 2013
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Assemblages; Atlantic Ocean; Biologic evolution; Cenozoic; Cyclicargolithus; DSDP Site 516; DSDP Site 588; DSDP Site 608; Deep Sea Drilling Project; Dictyococcites; IPOD; Leg 72; Leg 90; Leg 94; Lord Howe Rise; Lower Miocene; Marine environment; Microfossils; Miocene; Morphology; Nannofossils; Neogene; Noelaerhabdaceae; North Atlantic; Northeast Atlantic; Oligocene; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleoecology; Paleoenvironment; Paleogene; Plantae; Quantitative analysis; Reticulofenestra; Rio Grande Rise; SEM data; South Atlantic; South Pacific; Southwest Pacific; Tertiary; Upper Oligocene; West Pacific
Coordinates: N425012 N425013 W0230515 W0230515
S260642 S260642 E1611336 E1611336
S301636 S301635 W0351706 W0351707
Record ID: 2013100841
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands