Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme
Geochemical analysis of fossil foraminifera is a routine approach to paleoceaneanographic reconstruction. Certain stable isotopes and minor elements substituted into the CaCO3 lattice during calcification vary at predictable rates in response to changes in ambient seawater such as temperature, glaci...
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ftunivgeneve:oai:unige.ch:aou:unige:92414 2023-10-01T03:59:02+02:00 Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme Brown, Elizabeth A. Weinkauf, Manuel Hallock, Pamela Kucera, Michal 2016 https://archive-ouverte.unige.ch/unige:92414 eng eng info:eu-repo/semantics/altIdentifier/doi/10.1130/abs/2016AM-285668 https://archive-ouverte.unige.ch/unige:92414 unige:92414 info:eu-repo/semantics/ GSA Annual Meeting / Gillespie, A. & Cowan, D. (ed.), (2016) info:eu-repo/classification/ddc/550 Planktonic Foraminifera Morphology Morphometrics Systematics info:eu-repo/semantics/bookPart Text Chapitre d'actes 2016 ftunivgeneve https://doi.org/10.1130/abs/2016AM-285668 2023-09-07T07:36:58Z Geochemical analysis of fossil foraminifera is a routine approach to paleoceaneanographic reconstruction. Certain stable isotopes and minor elements substituted into the CaCO3 lattice during calcification vary at predictable rates in response to changes in ambient seawater such as temperature, glacial ice volume, salinity, water column structure, or productivity. Such rates vary, as shell development is influenced by species-specific offsets in isotopic fractionation during growth. Above all, paleo-reconstruction necessarily assumes the foraminifera assessed represent uniform species, incorporating seawater chemistry consistently through time. Interpretation of parameters that caused chemical or morphological changes in fossil shells is then extrapolated from living analogues. As foraminiferal species differ evolutionarily, and in physiological response to local environmental influences, their shape and chemistry is unsurprisingly diverse. The greater the extent of morphological plasticity, the more vulnerable the species is to biased or erroneous interpretation. A prime example is the Globigerinoides ruber-elongatus plexus. G. ruber (d'Orbigny 1839) is a common planktonic foraminifer used in studies of the upper mixed layer of low-latitude oceans since the Miocene. Taxonomic revisions since 1839 resulted in the inclusion of numerous transitional morphologies now known to be unique biological species. At least two of these (G. ruber & G. elongatus) substitute isotopes dissimilarly. Whether these morphospecies ought to be separated when used as a paleo-proxy – and how – is cause for consideration. Various criteria exist to differentiate morphologies, but their efficacy has not been tested quantitatively and they yield inconsistent geochemical data in different ocean basins. Here, we present morphometric and stable isotope analyses of coretop and downcore G. ruber and G. elongatus from the Atlantic and Pacific, identified using only three criteria: 1) final chamber compression, and 2) asymmetry, and 3) ... Book Part Planktonic foraminifera Université de Genève: Archive ouverte UNIGE Pacific Geological Society of America Abstracts with Programs, |
institution |
Open Polar |
collection |
Université de Genève: Archive ouverte UNIGE |
op_collection_id |
ftunivgeneve |
language |
English |
topic |
info:eu-repo/classification/ddc/550 Planktonic Foraminifera Morphology Morphometrics Systematics |
spellingShingle |
info:eu-repo/classification/ddc/550 Planktonic Foraminifera Morphology Morphometrics Systematics Brown, Elizabeth A. Weinkauf, Manuel Hallock, Pamela Kucera, Michal Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
topic_facet |
info:eu-repo/classification/ddc/550 Planktonic Foraminifera Morphology Morphometrics Systematics |
description |
Geochemical analysis of fossil foraminifera is a routine approach to paleoceaneanographic reconstruction. Certain stable isotopes and minor elements substituted into the CaCO3 lattice during calcification vary at predictable rates in response to changes in ambient seawater such as temperature, glacial ice volume, salinity, water column structure, or productivity. Such rates vary, as shell development is influenced by species-specific offsets in isotopic fractionation during growth. Above all, paleo-reconstruction necessarily assumes the foraminifera assessed represent uniform species, incorporating seawater chemistry consistently through time. Interpretation of parameters that caused chemical or morphological changes in fossil shells is then extrapolated from living analogues. As foraminiferal species differ evolutionarily, and in physiological response to local environmental influences, their shape and chemistry is unsurprisingly diverse. The greater the extent of morphological plasticity, the more vulnerable the species is to biased or erroneous interpretation. A prime example is the Globigerinoides ruber-elongatus plexus. G. ruber (d'Orbigny 1839) is a common planktonic foraminifer used in studies of the upper mixed layer of low-latitude oceans since the Miocene. Taxonomic revisions since 1839 resulted in the inclusion of numerous transitional morphologies now known to be unique biological species. At least two of these (G. ruber & G. elongatus) substitute isotopes dissimilarly. Whether these morphospecies ought to be separated when used as a paleo-proxy – and how – is cause for consideration. Various criteria exist to differentiate morphologies, but their efficacy has not been tested quantitatively and they yield inconsistent geochemical data in different ocean basins. Here, we present morphometric and stable isotope analyses of coretop and downcore G. ruber and G. elongatus from the Atlantic and Pacific, identified using only three criteria: 1) final chamber compression, and 2) asymmetry, and 3) ... |
format |
Book Part |
author |
Brown, Elizabeth A. Weinkauf, Manuel Hallock, Pamela Kucera, Michal |
author_facet |
Brown, Elizabeth A. Weinkauf, Manuel Hallock, Pamela Kucera, Michal |
author_sort |
Brown, Elizabeth A. |
title |
Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
title_short |
Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
title_full |
Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
title_fullStr |
Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
title_full_unstemmed |
Evaluating morphospace discontinuity within the Globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
title_sort |
evaluating morphospace discontinuity within the globigerinoides ruber-elongatus plexus, and the potential for a consistent fossil classification scheme |
publishDate |
2016 |
url |
https://archive-ouverte.unige.ch/unige:92414 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
GSA Annual Meeting / Gillespie, A. & Cowan, D. (ed.), (2016) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1130/abs/2016AM-285668 https://archive-ouverte.unige.ch/unige:92414 unige:92414 |
op_rights |
info:eu-repo/semantics/ |
op_doi |
https://doi.org/10.1130/abs/2016AM-285668 |
container_title |
Geological Society of America Abstracts with Programs, |
_version_ |
1778532432345038848 |