Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest.
Lower Eocene (Wasatchian-aged) sediments of the Margaret Formation on Ellesmere Island in Canada's High Arctic preserve evidence of a rainforest inhabited by alligators, turtles, and a diverse mammalian fauna. The mammalian fossils are fragmentary and often poorly preserved. Here, we offer an a...
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ftdoajarticles:oai:doaj.org/article:69ddf3b03c3a45199cd713e73a8cc634 2023-05-15T14:51:58+02:00 Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. Jaelyn J Eberle Wighart von Koenigswald David A Eberth 2020-01-01T00:00:00Z https://doi.org/10.1371/journal.pone.0239073 https://doaj.org/article/69ddf3b03c3a45199cd713e73a8cc634 EN eng Public Library of Science (PLoS) https://doi.org/10.1371/journal.pone.0239073 https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0239073 https://doaj.org/article/69ddf3b03c3a45199cd713e73a8cc634 PLoS ONE, Vol 15, Iss 9, p e0239073 (2020) Medicine R Science Q article 2020 ftdoajarticles https://doi.org/10.1371/journal.pone.0239073 2022-12-31T07:51:13Z Lower Eocene (Wasatchian-aged) sediments of the Margaret Formation on Ellesmere Island in Canada's High Arctic preserve evidence of a rainforest inhabited by alligators, turtles, and a diverse mammalian fauna. The mammalian fossils are fragmentary and often poorly preserved. Here, we offer an alternative method for their identification. Among the best preserved and extensive of the Eocene Arctic forests is the Strathcona Fiord Fossil Forest, which contains permineralized in situ tree stumps protruding from a prominent coal seam, but a paucity of vertebrate fossils. In 2010 and 2018, we recovered mammalian tooth fragments at the fossil forest, but they are so incomplete as to be undiagnostic by using their external morphology. We used a combination of light microscopy and SEM analysis to study the enamel microstructure of two tooth fragments from the fossil forest-NUFV2092B and 2092E. The results of our analysis indicate that NUFV2092B and 2092E have Coryphodon-enamel, which is characterized by vertical bodies that manifest as bands of nested chevrons or treelike structures visible in the tangential section under light microscopy. This enamel type is not found in other mammals known from the Arctic. Additionally, when studied under SEM, the enamel of NUFV2092B and 2092E has rounded prisms that open to one side and are surrounded by interprismatic matrix that is nearly parallel to the prisms, which also occurs in Coryphodon enamel, based on prior studies. The tooth fragments reported here, along with some poorly preserved bone fragments, thus far are the only documented vertebrate fossils from the Strathcona Fiord Fossil Forest. However, fossils of Coryphodon occur elsewhere in the Margaret Formation, so its presence at the fossil forest is not surprising. What is novel in our study is the way in which we identified the fossils using their enamel microstructure. Article in Journal/Newspaper Arctic Ellesmere Island Directory of Open Access Journals: DOAJ Articles Arctic Ellesmere Island Strathcona ENVELOPE(99.200,99.200,-67.417,-67.417) Strathcona Fiord ENVELOPE(-82.915,-82.915,78.719,78.719) PLOS ONE 15 9 e0239073 |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
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language |
English |
topic |
Medicine R Science Q |
spellingShingle |
Medicine R Science Q Jaelyn J Eberle Wighart von Koenigswald David A Eberth Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. |
topic_facet |
Medicine R Science Q |
description |
Lower Eocene (Wasatchian-aged) sediments of the Margaret Formation on Ellesmere Island in Canada's High Arctic preserve evidence of a rainforest inhabited by alligators, turtles, and a diverse mammalian fauna. The mammalian fossils are fragmentary and often poorly preserved. Here, we offer an alternative method for their identification. Among the best preserved and extensive of the Eocene Arctic forests is the Strathcona Fiord Fossil Forest, which contains permineralized in situ tree stumps protruding from a prominent coal seam, but a paucity of vertebrate fossils. In 2010 and 2018, we recovered mammalian tooth fragments at the fossil forest, but they are so incomplete as to be undiagnostic by using their external morphology. We used a combination of light microscopy and SEM analysis to study the enamel microstructure of two tooth fragments from the fossil forest-NUFV2092B and 2092E. The results of our analysis indicate that NUFV2092B and 2092E have Coryphodon-enamel, which is characterized by vertical bodies that manifest as bands of nested chevrons or treelike structures visible in the tangential section under light microscopy. This enamel type is not found in other mammals known from the Arctic. Additionally, when studied under SEM, the enamel of NUFV2092B and 2092E has rounded prisms that open to one side and are surrounded by interprismatic matrix that is nearly parallel to the prisms, which also occurs in Coryphodon enamel, based on prior studies. The tooth fragments reported here, along with some poorly preserved bone fragments, thus far are the only documented vertebrate fossils from the Strathcona Fiord Fossil Forest. However, fossils of Coryphodon occur elsewhere in the Margaret Formation, so its presence at the fossil forest is not surprising. What is novel in our study is the way in which we identified the fossils using their enamel microstructure. |
format |
Article in Journal/Newspaper |
author |
Jaelyn J Eberle Wighart von Koenigswald David A Eberth |
author_facet |
Jaelyn J Eberle Wighart von Koenigswald David A Eberth |
author_sort |
Jaelyn J Eberle |
title |
Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. |
title_short |
Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. |
title_full |
Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. |
title_fullStr |
Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. |
title_full_unstemmed |
Using tooth enamel microstructure to identify mammalian fossils at an Eocene Arctic forest. |
title_sort |
using tooth enamel microstructure to identify mammalian fossils at an eocene arctic forest. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2020 |
url |
https://doi.org/10.1371/journal.pone.0239073 https://doaj.org/article/69ddf3b03c3a45199cd713e73a8cc634 |
long_lat |
ENVELOPE(99.200,99.200,-67.417,-67.417) ENVELOPE(-82.915,-82.915,78.719,78.719) |
geographic |
Arctic Ellesmere Island Strathcona Strathcona Fiord |
geographic_facet |
Arctic Ellesmere Island Strathcona Strathcona Fiord |
genre |
Arctic Ellesmere Island |
genre_facet |
Arctic Ellesmere Island |
op_source |
PLoS ONE, Vol 15, Iss 9, p e0239073 (2020) |
op_relation |
https://doi.org/10.1371/journal.pone.0239073 https://doaj.org/toc/1932-6203 1932-6203 doi:10.1371/journal.pone.0239073 https://doaj.org/article/69ddf3b03c3a45199cd713e73a8cc634 |
op_doi |
https://doi.org/10.1371/journal.pone.0239073 |
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PLOS ONE |
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15 |
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e0239073 |
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