Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms
Petalichthyid and “acanthothoracid” placoderms have taken pivotal positionsin the debate on placoderm—and, by extension, jawed vertebrate—relationships owing to perceived similarities with the jawless vertebrates. Neurocranial characters are integral to current hypotheses of early gnathostome relati...
Published in: | Canadian Journal of Earth Sciences |
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Online Access: | http://hdl.handle.net/10044/1/80971 https://doi.org/10.1139/cjes-2020-0005 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/80971 2023-05-15T15:04:26+02:00 Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms Castiello, M Jerve, A Burton, MG Friedman, M Brazeau, M Commission of the European Communities 2020-06-12 http://hdl.handle.net/10044/1/80971 https://doi.org/10.1139/cjes-2020-0005 unknown NRC Research Press Canadian Journal of Earth Sciences 0008-4077 http://hdl.handle.net/10044/1/80971 doi:10.1139/cjes-2020-0005 311092 © 2020 Canadian Science Publishing 04 Earth Sciences Geology Journal Article 2020 ftimperialcol https://doi.org/10.1139/cjes-2020-0005 2021-02-04T23:39:13Z Petalichthyid and “acanthothoracid” placoderms have taken pivotal positionsin the debate on placoderm—and, by extension, jawed vertebrate—relationships owing to perceived similarities with the jawless vertebrates. Neurocranial characters are integral to current hypotheses of early gnathostome relationships. Here, we describe the three-dimensionally preserved neurocranial anatomy of the petalichthyid placoderm Ellopetalichthys scheii, from the Middle Devonian (early Eifelian) of Ellesmere Island, Canada. Using X-ray computed microtomography, we generated three-dimensional reconstructions of the endocranial surfaces, orbital walls, and cranial endocavity. These reconstructions verify the absence of a crus commune of the skeletal labyrinth and the complex shape of the petalichthyid endolympathic duct. Details of the craniothoracic joint and occipital musculature fossae help resolve the problematic comparative anatomy of the occipital surface of petalichthyids. These new data highlight similarities with arthrodire placoderms, consistent with older hypotheses of a sister-31group relationship between petalichthyids and that clade. Article in Journal/Newspaper Arctic Ellesmere Island Imperial College London: Spiral Arctic Canada Ellesmere Island Labyrinth ENVELOPE(160.833,160.833,-77.550,-77.550) Canadian Journal of Earth Sciences 58 1 93 104 |
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Open Polar |
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Imperial College London: Spiral |
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ftimperialcol |
language |
unknown |
topic |
04 Earth Sciences Geology |
spellingShingle |
04 Earth Sciences Geology Castiello, M Jerve, A Burton, MG Friedman, M Brazeau, M Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms |
topic_facet |
04 Earth Sciences Geology |
description |
Petalichthyid and “acanthothoracid” placoderms have taken pivotal positionsin the debate on placoderm—and, by extension, jawed vertebrate—relationships owing to perceived similarities with the jawless vertebrates. Neurocranial characters are integral to current hypotheses of early gnathostome relationships. Here, we describe the three-dimensionally preserved neurocranial anatomy of the petalichthyid placoderm Ellopetalichthys scheii, from the Middle Devonian (early Eifelian) of Ellesmere Island, Canada. Using X-ray computed microtomography, we generated three-dimensional reconstructions of the endocranial surfaces, orbital walls, and cranial endocavity. These reconstructions verify the absence of a crus commune of the skeletal labyrinth and the complex shape of the petalichthyid endolympathic duct. Details of the craniothoracic joint and occipital musculature fossae help resolve the problematic comparative anatomy of the occipital surface of petalichthyids. These new data highlight similarities with arthrodire placoderms, consistent with older hypotheses of a sister-31group relationship between petalichthyids and that clade. |
author2 |
Commission of the European Communities |
format |
Article in Journal/Newspaper |
author |
Castiello, M Jerve, A Burton, MG Friedman, M Brazeau, M |
author_facet |
Castiello, M Jerve, A Burton, MG Friedman, M Brazeau, M |
author_sort |
Castiello, M |
title |
Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms |
title_short |
Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms |
title_full |
Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms |
title_fullStr |
Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms |
title_full_unstemmed |
Endocranial morphology of the petalichthyid placoderm Ellopetalichthys scheii from the Middle Devonian of Arctic Canada, with remarks on the inner ear and neck joint morphology of placoderms |
title_sort |
endocranial morphology of the petalichthyid placoderm ellopetalichthys scheii from the middle devonian of arctic canada, with remarks on the inner ear and neck joint morphology of placoderms |
publisher |
NRC Research Press |
publishDate |
2020 |
url |
http://hdl.handle.net/10044/1/80971 https://doi.org/10.1139/cjes-2020-0005 |
long_lat |
ENVELOPE(160.833,160.833,-77.550,-77.550) |
geographic |
Arctic Canada Ellesmere Island Labyrinth |
geographic_facet |
Arctic Canada Ellesmere Island Labyrinth |
genre |
Arctic Ellesmere Island |
genre_facet |
Arctic Ellesmere Island |
op_relation |
Canadian Journal of Earth Sciences 0008-4077 http://hdl.handle.net/10044/1/80971 doi:10.1139/cjes-2020-0005 311092 |
op_rights |
© 2020 Canadian Science Publishing |
op_doi |
https://doi.org/10.1139/cjes-2020-0005 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
58 |
container_issue |
1 |
container_start_page |
93 |
op_container_end_page |
104 |
_version_ |
1766336208696246272 |