Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia)
Abstract The otic region in the skull of archeocetes and odontocetes is compared and interpreted with special emphasis on the morphology and suspension of the ear bones. In archeocetes, the periotic was obviously separate from the mastoid but still integrated within the skull via a long anterior and...
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crwiley:10.1002/aja.1001770306 2024-06-02T08:15:17+00:00 Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) Oelschläger, Helmut A. 1986 http://dx.doi.org/10.1002/aja.1001770306 http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faja.1001770306 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faja.1001770306 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aja.1001770306 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor American Journal of Anatomy volume 177, issue 3, page 353-368 ISSN 0002-9106 1553-0795 journal-article 1986 crwiley https://doi.org/10.1002/aja.1001770306 2024-05-03T11:35:05Z Abstract The otic region in the skull of archeocetes and odontocetes is compared and interpreted with special emphasis on the morphology and suspension of the ear bones. In archeocetes, the periotic was obviously separate from the mastoid but still integrated within the skull via a long anterior and posterior process. The rotation of the cochlear part of the periotic was already obvious. The tympanic bone was attached to a decreasing number of neighboring elements, with the periotic becoming more and more important in the later archeocetes. The accessory air sacs of the tympanic cavity had invaded some of the adjacent skeletal elements and attained a moderate‐to‐remarkable extension. In the evolution of the odontocetes, the periotic and tympanic were successively uncoupled from the skull and combined to a new morphological and functional unit (tympanoperiotic complex). This uncoupling was mainly achieved by shortening the periotical processes and simultaneously extending the tympanic air sacs. For functional reasons, however, the periotic (posterior process) stayed in immediate contact with the mastoid, the latter remaining in the lateral wall of the skull. In advanced marine dolphins, the bony sheaths of the accessory air sacs are largely reduced, presumably because of volume fluctuations in the tympanic cavity during diving. The perfect uncoupling of the ear bones from the skull obviously was an essential prerequisite for directional hearing, for effective ultrasound orientation and communication, and finally, for the striking development of the dolphin brain. Article in Journal/Newspaper toothed whales Wiley Online Library American Journal of Anatomy 177 3 353 368 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract The otic region in the skull of archeocetes and odontocetes is compared and interpreted with special emphasis on the morphology and suspension of the ear bones. In archeocetes, the periotic was obviously separate from the mastoid but still integrated within the skull via a long anterior and posterior process. The rotation of the cochlear part of the periotic was already obvious. The tympanic bone was attached to a decreasing number of neighboring elements, with the periotic becoming more and more important in the later archeocetes. The accessory air sacs of the tympanic cavity had invaded some of the adjacent skeletal elements and attained a moderate‐to‐remarkable extension. In the evolution of the odontocetes, the periotic and tympanic were successively uncoupled from the skull and combined to a new morphological and functional unit (tympanoperiotic complex). This uncoupling was mainly achieved by shortening the periotical processes and simultaneously extending the tympanic air sacs. For functional reasons, however, the periotic (posterior process) stayed in immediate contact with the mastoid, the latter remaining in the lateral wall of the skull. In advanced marine dolphins, the bony sheaths of the accessory air sacs are largely reduced, presumably because of volume fluctuations in the tympanic cavity during diving. The perfect uncoupling of the ear bones from the skull obviously was an essential prerequisite for directional hearing, for effective ultrasound orientation and communication, and finally, for the striking development of the dolphin brain. |
format |
Article in Journal/Newspaper |
author |
Oelschläger, Helmut A. |
spellingShingle |
Oelschläger, Helmut A. Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) |
author_facet |
Oelschläger, Helmut A. |
author_sort |
Oelschläger, Helmut A. |
title |
Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) |
title_short |
Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) |
title_full |
Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) |
title_fullStr |
Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) |
title_full_unstemmed |
Comparative morphology and evolution of the otic region in toothed whales (Cetacea, Mammalia) |
title_sort |
comparative morphology and evolution of the otic region in toothed whales (cetacea, mammalia) |
publisher |
Wiley |
publishDate |
1986 |
url |
http://dx.doi.org/10.1002/aja.1001770306 http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faja.1001770306 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faja.1001770306 https://onlinelibrary.wiley.com/doi/pdf/10.1002/aja.1001770306 |
genre |
toothed whales |
genre_facet |
toothed whales |
op_source |
American Journal of Anatomy volume 177, issue 3, page 353-368 ISSN 0002-9106 1553-0795 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/aja.1001770306 |
container_title |
American Journal of Anatomy |
container_volume |
177 |
container_issue |
3 |
container_start_page |
353 |
op_container_end_page |
368 |
_version_ |
1800739399840825344 |