Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike

Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of ne...

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Autores principales: Barreda, Viviana Dora, Cúneo, Nestor Rubén, Scasso, Roberto Adrian
Publicado: 2012
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19326203_v7_n12_p_Barreda
http://hdl.handle.net/20.500.12110/paper_19326203_v7_n12_p_Barreda
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spelling paper:paper_19326203_v7_n12_p_Barreda2023-06-08T16:31:02Z Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike Barreda, Viviana Dora Cúneo, Nestor Rubén Scasso, Roberto Adrian article biodiversity Cenozoic Cheirolepidiaceae Classopollis conifer Danian end Cretaceous mass extinction Eocene flora gymnosperm Mesozoa New Zealand nonhuman North America Northern Hemisphere Paleocene palynology population abundance Southern Hemisphere species extinction Argentina Biodiversity Extinction, Biological Flowers Geography Gymnosperms Pollen Spores Time Factors Cheirolepidiaceae Classopollis Coniferophyta Embryophyta Gymnospermae Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of nearly all plant groups across the K/Pg interval. Minimum diversity occurs during the earliest Danian, but only a few palynomorphs show true extinctions. The low extinction rate is similar to previous observations from New Zealand. The differing responses between the Southern and Northern hemispheres could be related to the attenuation of damage with increased distance from the impact site, to hemispheric differences in extinction severity, or to both effects. Legacy effects of the terminal Cretaceous event also provide a plausible, partial explanation for the fact that Paleocene and Eocene macrofloras from Patagonia are among the most diverse known globally. Also of great interest, earliest Danian assemblages are dominated by the gymnosperm palynomorphs Classopollis of the extinct Mesozoic conifer family Cheirolepidiaceae. The expansion of Classopollis after the boundary in Patagonia is another example of typically Mesozoic plant lineages surviving into the Cenozoic in southern Gondwanan areas, and this greatly supports previous hypotheses of high latitude southern regions as biodiversity refugia during the end-Cretaceous global crisis. © 2012 Barreda et al. Fil:Barreda, V.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Cúneo, N.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Scasso, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19326203_v7_n12_p_Barreda http://hdl.handle.net/20.500.12110/paper_19326203_v7_n12_p_Barreda
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic article
biodiversity
Cenozoic
Cheirolepidiaceae
Classopollis
conifer
Danian
end Cretaceous mass extinction
Eocene
flora
gymnosperm
Mesozoa
New Zealand
nonhuman
North America
Northern Hemisphere
Paleocene
palynology
population abundance
Southern Hemisphere
species extinction
Argentina
Biodiversity
Extinction, Biological
Flowers
Geography
Gymnosperms
Pollen
Spores
Time Factors
Cheirolepidiaceae
Classopollis
Coniferophyta
Embryophyta
Gymnospermae
spellingShingle article
biodiversity
Cenozoic
Cheirolepidiaceae
Classopollis
conifer
Danian
end Cretaceous mass extinction
Eocene
flora
gymnosperm
Mesozoa
New Zealand
nonhuman
North America
Northern Hemisphere
Paleocene
palynology
population abundance
Southern Hemisphere
species extinction
Argentina
Biodiversity
Extinction, Biological
Flowers
Geography
Gymnosperms
Pollen
Spores
Time Factors
Cheirolepidiaceae
Classopollis
Coniferophyta
Embryophyta
Gymnospermae
Barreda, Viviana Dora
Cúneo, Nestor Rubén
Scasso, Roberto Adrian
Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike
topic_facet article
biodiversity
Cenozoic
Cheirolepidiaceae
Classopollis
conifer
Danian
end Cretaceous mass extinction
Eocene
flora
gymnosperm
Mesozoa
New Zealand
nonhuman
North America
Northern Hemisphere
Paleocene
palynology
population abundance
Southern Hemisphere
species extinction
Argentina
Biodiversity
Extinction, Biological
Flowers
Geography
Gymnosperms
Pollen
Spores
Time Factors
Cheirolepidiaceae
Classopollis
Coniferophyta
Embryophyta
Gymnospermae
description Nearly all data regarding land-plant turnover across the Cretaceous/Paleogene boundary come from western North America, relatively close to the Chicxulub, Mexico impact site. Here, we present a palynological analysis of a section in Patagonia that shows a marked fall in diversity and abundance of nearly all plant groups across the K/Pg interval. Minimum diversity occurs during the earliest Danian, but only a few palynomorphs show true extinctions. The low extinction rate is similar to previous observations from New Zealand. The differing responses between the Southern and Northern hemispheres could be related to the attenuation of damage with increased distance from the impact site, to hemispheric differences in extinction severity, or to both effects. Legacy effects of the terminal Cretaceous event also provide a plausible, partial explanation for the fact that Paleocene and Eocene macrofloras from Patagonia are among the most diverse known globally. Also of great interest, earliest Danian assemblages are dominated by the gymnosperm palynomorphs Classopollis of the extinct Mesozoic conifer family Cheirolepidiaceae. The expansion of Classopollis after the boundary in Patagonia is another example of typically Mesozoic plant lineages surviving into the Cenozoic in southern Gondwanan areas, and this greatly supports previous hypotheses of high latitude southern regions as biodiversity refugia during the end-Cretaceous global crisis. © 2012 Barreda et al.
author Barreda, Viviana Dora
Cúneo, Nestor Rubén
Scasso, Roberto Adrian
author_facet Barreda, Viviana Dora
Cúneo, Nestor Rubén
Scasso, Roberto Adrian
author_sort Barreda, Viviana Dora
title Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike
title_short Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike
title_full Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike
title_fullStr Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike
title_full_unstemmed Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike
title_sort cretaceous/paleogene floral turnover in patagonia: drop in diversity, low extinction, and a classopollis spike
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19326203_v7_n12_p_Barreda
http://hdl.handle.net/20.500.12110/paper_19326203_v7_n12_p_Barreda
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AT scassorobertoadrian cretaceouspaleogenefloralturnoverinpatagoniadropindiversitylowextinctionandaclassopollisspike
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