Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity
The Cambrian evolutionary radiations are marked by spectacular biotic turnovers and the establishment of increasingly tiered food chains. At the base of these food chains are primary producers, which in the Cambrian fossil record are chiefly represented among organic-walled microfossils. The majorit...
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2022
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ftbioone:10.1017/pab.2022.12 2024-06-02T08:07:29+00:00 Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity Elise Wallet Sebastian Willman Ben J. Slater Elise Wallet Sebastian Willman Ben J. Slater world 2022-10-20 text/HTML https://doi.org/10.1017/pab.2022.12 en eng The Paleontological Society doi:10.1017/pab.2022.12 All rights reserved. https://doi.org/10.1017/pab.2022.12 Text 2022 ftbioone https://doi.org/10.1017/pab.2022.12 2024-05-07T00:48:07Z The Cambrian evolutionary radiations are marked by spectacular biotic turnovers and the establishment of increasingly tiered food chains. At the base of these food chains are primary producers, which in the Cambrian fossil record are chiefly represented among organic-walled microfossils. The majority of these microfossil remains have traditionally been attributed to an informal category of incertae sedis called “acritarchs,” based entirely on form taxonomy. Acritarch form taxa have been intensely used for biostratigraphy and in large-scale studies of phytoplankton diversity. However, both prospects have been challenged by cases of taxonomic inconsistencies and oversplitting arising from the large phenotypic plasticity seen among these microfossils. The acritarch form genus Skiagia stands as an ideal case study to explore these taxonomic challenges, because it encompasses a number of form species widely used in lower Cambrian biostratigraphy. Moreover, subtle morphological differences among Skiagia species were suggested to underlie key evolutionary innovations toward complex reproductive strategies. Here we apply a multivariate morphometric approach to investigate the morphological variation of Skiagia-plexus acritarchs using an assemblage sourced from the Buen Formation (Cambrian Series 2, Stages 3–4) of North Greenland. Our analysis showed that the species-level classification of Skiagia discretizes a continuous spectrum of morphologies. While these findings bring important taxonomic and biostratigraphic hurdles to light, the unequal frequency distribution of life cycle stages among Skiagia species suggests that certain elements of phytoplankton paleobiology are nonetheless captured by Skiagia form taxonomy. These results demonstrate the value of using morphometric tools to explore acritarch phenotypic plasticity and its potential ontogenetic and paleoecological drivers in Cambrian ecosystems. Text Greenland North Greenland BioOne Online Journals Greenland Paleobiology 48 4 576 600 |
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English |
description |
The Cambrian evolutionary radiations are marked by spectacular biotic turnovers and the establishment of increasingly tiered food chains. At the base of these food chains are primary producers, which in the Cambrian fossil record are chiefly represented among organic-walled microfossils. The majority of these microfossil remains have traditionally been attributed to an informal category of incertae sedis called “acritarchs,” based entirely on form taxonomy. Acritarch form taxa have been intensely used for biostratigraphy and in large-scale studies of phytoplankton diversity. However, both prospects have been challenged by cases of taxonomic inconsistencies and oversplitting arising from the large phenotypic plasticity seen among these microfossils. The acritarch form genus Skiagia stands as an ideal case study to explore these taxonomic challenges, because it encompasses a number of form species widely used in lower Cambrian biostratigraphy. Moreover, subtle morphological differences among Skiagia species were suggested to underlie key evolutionary innovations toward complex reproductive strategies. Here we apply a multivariate morphometric approach to investigate the morphological variation of Skiagia-plexus acritarchs using an assemblage sourced from the Buen Formation (Cambrian Series 2, Stages 3–4) of North Greenland. Our analysis showed that the species-level classification of Skiagia discretizes a continuous spectrum of morphologies. While these findings bring important taxonomic and biostratigraphic hurdles to light, the unequal frequency distribution of life cycle stages among Skiagia species suggests that certain elements of phytoplankton paleobiology are nonetheless captured by Skiagia form taxonomy. These results demonstrate the value of using morphometric tools to explore acritarch phenotypic plasticity and its potential ontogenetic and paleoecological drivers in Cambrian ecosystems. |
author2 |
Elise Wallet Sebastian Willman Ben J. Slater |
format |
Text |
author |
Elise Wallet Sebastian Willman Ben J. Slater |
spellingShingle |
Elise Wallet Sebastian Willman Ben J. Slater Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity |
author_facet |
Elise Wallet Sebastian Willman Ben J. Slater |
author_sort |
Elise Wallet |
title |
Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity |
title_short |
Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity |
title_full |
Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity |
title_fullStr |
Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity |
title_full_unstemmed |
Morphometric analysis of Skiagia-plexus acritarchs from the early Cambrian of North Greenland: toward a meaningful evaluation of phenotypic plasticity |
title_sort |
morphometric analysis of skiagia-plexus acritarchs from the early cambrian of north greenland: toward a meaningful evaluation of phenotypic plasticity |
publisher |
The Paleontological Society |
publishDate |
2022 |
url |
https://doi.org/10.1017/pab.2022.12 |
op_coverage |
world |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland North Greenland |
genre_facet |
Greenland North Greenland |
op_source |
https://doi.org/10.1017/pab.2022.12 |
op_relation |
doi:10.1017/pab.2022.12 |
op_rights |
All rights reserved. |
op_doi |
https://doi.org/10.1017/pab.2022.12 |
container_title |
Paleobiology |
container_volume |
48 |
container_issue |
4 |
container_start_page |
576 |
op_container_end_page |
600 |
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1800752564401078272 |