A Comparative Study of End-Devonian Tetrapod Material from Greenland
The impact of the end-Devonian mass extinction (the Hangenberg extinction) on tetrapods is not well understood. One issue is that we have very little knowledge of the Devonian tetrapod fauna that immediately preceded, and experienced, the mass extinction. New specimens from an early tetrapod bone be...
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Uppsala universitet, Institutionen för geovetenskaper
2024
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ftuppsalauniv:oai:DiVA.org:uu-531070 2024-09-09T19:38:45+00:00 A Comparative Study of End-Devonian Tetrapod Material from Greenland Sheng, Rebecca Ruo 2024 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-531070 eng eng Uppsala universitet, Institutionen för geovetenskaper Examensarbete vid Institutionen för geovetenskaper, 1650-6553 625 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-531070 info:eu-repo/semantics/openAccess early tetrapod fossil Greenland Devonian synchrotron tomography Evolutionary Biology Evolutionsbiologi Geosciences Multidisciplinary Multidisciplinär geovetenskap Student thesis info:eu-repo/semantics/bachelorThesis text 2024 ftuppsalauniv 2024-06-18T23:50:51Z The impact of the end-Devonian mass extinction (the Hangenberg extinction) on tetrapods is not well understood. One issue is that we have very little knowledge of the Devonian tetrapod fauna that immediately preceded, and experienced, the mass extinction. New specimens from an early tetrapod bone bed of the latest Famennian, Stensiö Bjerg Formation of Celsius Bjerg, East Greenland have the potential to shed light on this problem. In this study, five new well-preserved specimens are presented: a partial skull, two humeri, a left pelvis, and a strange vertebral element. The specimens were imaged using propagation phase-contrast synchrotron microtomography (PPC-SRμCT), and then virtually segmented and rendered. The partial skull and left pelvis share many similarities with Ichthyostega and Acanthostega, but also have some distinctive features. Notably, the epipterygoid does not articulate with the skull roof, the fenestra vestibuli appears to have an anterior lobe, the postorbital has a posteroventral process, and there is a sharp contrast between the rugose dermal ornament of the skull roof and the unornamented cheek. In addition, the partial skull is box-like in shape and has a laterally facing orbit, which are features seen in some Carboniferous tetrapods. Among other characters, the left pelvis has a differently curving posterior iliac process, and differently shaped ischium and anterior pubic margin compared to Ichthyostega and Acanthostega. The acetabulum of the left pelvis is also lacking a posterior notch, a feature seen in many other early tetrapods. The humeri presented in this thesis are curiously similar to the isolated tetrapod humerus from the Catskill Formation, Pennsylvania, USA known as ANSP 21350. In fact, they are more similar to each other and to ANSP 21350 than to any other early tetrapod humeri. This is in large part due to a distinctly distal supinator ridge which was previously only known from ANSP 21350. The mysterious vertebral element does not resemble any known early tetrapod ... Bachelor Thesis East Greenland Greenland Uppsala University: Publications (DiVA) Celsius Bjerg ENVELOPE(-23.250,-23.250,73.117,73.117) Greenland |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
early tetrapod fossil Greenland Devonian synchrotron tomography Evolutionary Biology Evolutionsbiologi Geosciences Multidisciplinary Multidisciplinär geovetenskap |
spellingShingle |
early tetrapod fossil Greenland Devonian synchrotron tomography Evolutionary Biology Evolutionsbiologi Geosciences Multidisciplinary Multidisciplinär geovetenskap Sheng, Rebecca Ruo A Comparative Study of End-Devonian Tetrapod Material from Greenland |
topic_facet |
early tetrapod fossil Greenland Devonian synchrotron tomography Evolutionary Biology Evolutionsbiologi Geosciences Multidisciplinary Multidisciplinär geovetenskap |
description |
The impact of the end-Devonian mass extinction (the Hangenberg extinction) on tetrapods is not well understood. One issue is that we have very little knowledge of the Devonian tetrapod fauna that immediately preceded, and experienced, the mass extinction. New specimens from an early tetrapod bone bed of the latest Famennian, Stensiö Bjerg Formation of Celsius Bjerg, East Greenland have the potential to shed light on this problem. In this study, five new well-preserved specimens are presented: a partial skull, two humeri, a left pelvis, and a strange vertebral element. The specimens were imaged using propagation phase-contrast synchrotron microtomography (PPC-SRμCT), and then virtually segmented and rendered. The partial skull and left pelvis share many similarities with Ichthyostega and Acanthostega, but also have some distinctive features. Notably, the epipterygoid does not articulate with the skull roof, the fenestra vestibuli appears to have an anterior lobe, the postorbital has a posteroventral process, and there is a sharp contrast between the rugose dermal ornament of the skull roof and the unornamented cheek. In addition, the partial skull is box-like in shape and has a laterally facing orbit, which are features seen in some Carboniferous tetrapods. Among other characters, the left pelvis has a differently curving posterior iliac process, and differently shaped ischium and anterior pubic margin compared to Ichthyostega and Acanthostega. The acetabulum of the left pelvis is also lacking a posterior notch, a feature seen in many other early tetrapods. The humeri presented in this thesis are curiously similar to the isolated tetrapod humerus from the Catskill Formation, Pennsylvania, USA known as ANSP 21350. In fact, they are more similar to each other and to ANSP 21350 than to any other early tetrapod humeri. This is in large part due to a distinctly distal supinator ridge which was previously only known from ANSP 21350. The mysterious vertebral element does not resemble any known early tetrapod ... |
format |
Bachelor Thesis |
author |
Sheng, Rebecca Ruo |
author_facet |
Sheng, Rebecca Ruo |
author_sort |
Sheng, Rebecca Ruo |
title |
A Comparative Study of End-Devonian Tetrapod Material from Greenland |
title_short |
A Comparative Study of End-Devonian Tetrapod Material from Greenland |
title_full |
A Comparative Study of End-Devonian Tetrapod Material from Greenland |
title_fullStr |
A Comparative Study of End-Devonian Tetrapod Material from Greenland |
title_full_unstemmed |
A Comparative Study of End-Devonian Tetrapod Material from Greenland |
title_sort |
comparative study of end-devonian tetrapod material from greenland |
publisher |
Uppsala universitet, Institutionen för geovetenskaper |
publishDate |
2024 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-531070 |
long_lat |
ENVELOPE(-23.250,-23.250,73.117,73.117) |
geographic |
Celsius Bjerg Greenland |
geographic_facet |
Celsius Bjerg Greenland |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_relation |
Examensarbete vid Institutionen för geovetenskaper, 1650-6553 625 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-531070 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1809907663291547648 |