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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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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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 |
work_keys_str_mv |
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_version_ |
1768541819116716032 |