Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications
A new species of the unusual dinoflagellate cyst genus Geonettia de Verteuil and Norris, 1996a is here described from the Pliocene of the western North Atlantic and eastern England. Geonettia waltonensis new species is only the second species to be formally described for this genus, whose type, G. c...
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crcambridgeupr:10.1017/s0022336000033023 2024-03-03T08:47:01+00:00 Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications Head, Martin J. 2000 http://dx.doi.org/10.1017/s0022336000033023 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000033023 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Paleontology volume 74, issue 5, page 812-827 ISSN 0022-3360 1937-2337 Paleontology journal-article 2000 crcambridgeupr https://doi.org/10.1017/s0022336000033023 2024-02-08T08:42:00Z A new species of the unusual dinoflagellate cyst genus Geonettia de Verteuil and Norris, 1996a is here described from the Pliocene of the western North Atlantic and eastern England. Geonettia waltonensis new species is only the second species to be formally described for this genus, whose type, G. clineae de Verteuil and Norris, 1996a, has a range of Miocene through Pliocene. Geonettia is a gonyaulacalean, goniodomacean genus of the subfamily Pyrodinioideae and is closely related to Eocladopyxis Morgenroth, 1966 and Capisocysta Warny and Wrenn, 1997, also found in the Cenozoic. However, Geonettia is the only known dinoflagellate cyst genus to have plates that dissociate extensively on both epi- and hypocyst during excystment. Geonettia waltonensis has this style of excystment, but its hypocystal tabulation is more akin to Capisocysta lata Head, 1998a than to G. clineae. Comparison of tabulation and other morphological features suggests that during the late Miocene, Capisocysta lata evolved from Geonettia waltonensis or a closely related species through failure of its epicystal plates to dissociate. Geonettia waltonensis probably did not evolve directly from G. clineae but may represent a separate lineage within Geonettia that arose during the Miocene. Article in Journal/Newspaper North Atlantic Cambridge University Press Journal of Paleontology 74 5 812 827 |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Paleontology |
spellingShingle |
Paleontology Head, Martin J. Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications |
topic_facet |
Paleontology |
description |
A new species of the unusual dinoflagellate cyst genus Geonettia de Verteuil and Norris, 1996a is here described from the Pliocene of the western North Atlantic and eastern England. Geonettia waltonensis new species is only the second species to be formally described for this genus, whose type, G. clineae de Verteuil and Norris, 1996a, has a range of Miocene through Pliocene. Geonettia is a gonyaulacalean, goniodomacean genus of the subfamily Pyrodinioideae and is closely related to Eocladopyxis Morgenroth, 1966 and Capisocysta Warny and Wrenn, 1997, also found in the Cenozoic. However, Geonettia is the only known dinoflagellate cyst genus to have plates that dissociate extensively on both epi- and hypocyst during excystment. Geonettia waltonensis has this style of excystment, but its hypocystal tabulation is more akin to Capisocysta lata Head, 1998a than to G. clineae. Comparison of tabulation and other morphological features suggests that during the late Miocene, Capisocysta lata evolved from Geonettia waltonensis or a closely related species through failure of its epicystal plates to dissociate. Geonettia waltonensis probably did not evolve directly from G. clineae but may represent a separate lineage within Geonettia that arose during the Miocene. |
format |
Article in Journal/Newspaper |
author |
Head, Martin J. |
author_facet |
Head, Martin J. |
author_sort |
Head, Martin J. |
title |
Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications |
title_short |
Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications |
title_full |
Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications |
title_fullStr |
Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications |
title_full_unstemmed |
Geonettia waltonensis , a new goniodomacean dinoflagellate from the Pliocene of the North Atlantic region, and its evolutionary implications |
title_sort |
geonettia waltonensis , a new goniodomacean dinoflagellate from the pliocene of the north atlantic region, and its evolutionary implications |
publisher |
Cambridge University Press (CUP) |
publishDate |
2000 |
url |
http://dx.doi.org/10.1017/s0022336000033023 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000033023 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal of Paleontology volume 74, issue 5, page 812-827 ISSN 0022-3360 1937-2337 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0022336000033023 |
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Journal of Paleontology |
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74 |
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5 |
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812 |
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827 |
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1792503152367370240 |