A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula
The new genus and species Llanocetus denticrenatus is described based on a cranial endocast and portion of a dentary fragment bearing two teeth from the Eocene La Meseta Formation, Seymour Island, Antarctic Penninsula. Llanocetus new genus is designated the type genus for the new family Llanocetidae...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Canadian Science Publishing
1989
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Online Access: | http://dx.doi.org/10.1139/f89-273 http://www.nrcresearchpress.com/doi/pdf/10.1139/f89-273 |
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crcansciencepubl:10.1139/f89-273 2024-10-06T13:44:14+00:00 A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula Mitchell, Edward D. 1989 http://dx.doi.org/10.1139/f89-273 http://www.nrcresearchpress.com/doi/pdf/10.1139/f89-273 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 46, issue 12, page 2219-2235 ISSN 0706-652X 1205-7533 journal-article 1989 crcansciencepubl https://doi.org/10.1139/f89-273 2024-09-12T04:13:26Z The new genus and species Llanocetus denticrenatus is described based on a cranial endocast and portion of a dentary fragment bearing two teeth from the Eocene La Meseta Formation, Seymour Island, Antarctic Penninsula. Llanocetus new genus is designated the type genus for the new family Llanocetidae. The Llanocetidae is placed within the new infraorder Crenaticeti, co-ordinate with the new Mysticete infraorder Chaeomysticeti. Llanocetus denticrenatus new species shows relationship with both Archaeoceti and Mysticeti. Revision of archaeocete and mysticete classification includes proposal of the new taxa Kekenodontinae, Mammalodontidae, and the new ranks Protocetoidea, Remingtonocetoidea, Basilosauroidea, and Eschrichtioidea. The endocast shows evidence of intracranial retial hypertrophy, taken as evidence of enhanced diving abilities. The large deeply notched teeth are widely spaced on the lower jaw. I hypothesize that filter feeding in whales arose first in species in which teeth with deep notches, forming widey spaced tubercles, comprised part of a straining apparatus analogous to the serrated teeth of the phocid seal Lobodon carcinophagus. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Lobodon carcinophagus Seymour Island Canadian Science Publishing Antarctic Antarctic Peninsula Seymour ENVELOPE(-56.767,-56.767,-64.283,-64.283) Seymour Island ENVELOPE(-56.750,-56.750,-64.283,-64.283) Canadian Journal of Fisheries and Aquatic Sciences 46 12 2219 2235 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
The new genus and species Llanocetus denticrenatus is described based on a cranial endocast and portion of a dentary fragment bearing two teeth from the Eocene La Meseta Formation, Seymour Island, Antarctic Penninsula. Llanocetus new genus is designated the type genus for the new family Llanocetidae. The Llanocetidae is placed within the new infraorder Crenaticeti, co-ordinate with the new Mysticete infraorder Chaeomysticeti. Llanocetus denticrenatus new species shows relationship with both Archaeoceti and Mysticeti. Revision of archaeocete and mysticete classification includes proposal of the new taxa Kekenodontinae, Mammalodontidae, and the new ranks Protocetoidea, Remingtonocetoidea, Basilosauroidea, and Eschrichtioidea. The endocast shows evidence of intracranial retial hypertrophy, taken as evidence of enhanced diving abilities. The large deeply notched teeth are widely spaced on the lower jaw. I hypothesize that filter feeding in whales arose first in species in which teeth with deep notches, forming widey spaced tubercles, comprised part of a straining apparatus analogous to the serrated teeth of the phocid seal Lobodon carcinophagus. |
format |
Article in Journal/Newspaper |
author |
Mitchell, Edward D. |
spellingShingle |
Mitchell, Edward D. A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula |
author_facet |
Mitchell, Edward D. |
author_sort |
Mitchell, Edward D. |
title |
A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula |
title_short |
A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula |
title_full |
A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula |
title_fullStr |
A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula |
title_full_unstemmed |
A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula |
title_sort |
new cetacean from the late eocene la meseta formation seymour island, antarctic peninsula |
publisher |
Canadian Science Publishing |
publishDate |
1989 |
url |
http://dx.doi.org/10.1139/f89-273 http://www.nrcresearchpress.com/doi/pdf/10.1139/f89-273 |
long_lat |
ENVELOPE(-56.767,-56.767,-64.283,-64.283) ENVELOPE(-56.750,-56.750,-64.283,-64.283) |
geographic |
Antarctic Antarctic Peninsula Seymour Seymour Island |
geographic_facet |
Antarctic Antarctic Peninsula Seymour Seymour Island |
genre |
Antarc* Antarctic Antarctic Peninsula Lobodon carcinophagus Seymour Island |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Lobodon carcinophagus Seymour Island |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 46, issue 12, page 2219-2235 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f89-273 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
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46 |
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12 |
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2219 |
op_container_end_page |
2235 |
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1812182631484227584 |