The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism
- Autores
- Loza, Cleopatra Mara; Scarano, Alejo Carlos; Galliari, Fernando Carlos; Soibelzon, Leopoldo Héctor; Negrete, Javier; Carlini, Alfredo Armando
- Año de publicación
- 2018
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- Here we describe and explore for the first time the ontogeny and sexual dimorphism of the auditory region of Otaria byronia. We studied the tympanic region of skulls of 237 specimens of different ages and sexes. Geometric morphometric methods were used to analyze the tympanic bulla. In addition, 3D reconstructions of the tympanic bulla were performed using computed tomography analysis scans and a serial wearing technique. We provide a description of the external and internal morphology of the tympanic bulla in both sexes and across different stages (bioclasses). The average shape of the bulla in O. byronia has a subtriangular contour, with variations between sexes and ages. Each stage (bioclasses I, II, and III) is characterized by the respective mean shape of the tympanic bulla and designated as a morphoclass (1, 2, and 3). In all cases, the ectotympanic shows greater surface area than the endotympanic, as in other otariids, in contrast to Phocidae. During ontogeny, the relative size of the ectotympanic increases, growing in all directions and covering the endotympanic. This pattern is seen to the greatest extent in adult males, in which the ectotympanic forms an extremely well-developed apophysis jugulare. No differences in internal morphology of the tympanic cavity were recorded between ages and sexes. The bulla does not increase in thickness in successive age classes; in fact, the walls are extremely thin in the adult stages, despite the extensive development of its processes. This pattern is opposite that observed in Phocidae. In morphoclass 3, adult males older than 7 years undergo hypermorphic change that results in a peramorphic condition when compared to adult females. These changes probably follow the same pattern shown by the rest of the skull and contribute to the marked sexual dimorphism of the species.
Facultad de Ciencias Naturales y Museo - Materia
-
Ciencias Naturales
ontogeny
Otaria byronia
sexual dimorphism
South American sea lion
tympanic bulla - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/127129
Ver los metadatos del registro completo
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The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphismLoza, Cleopatra MaraScarano, Alejo CarlosGalliari, Fernando CarlosSoibelzon, Leopoldo HéctorNegrete, JavierCarlini, Alfredo ArmandoCiencias NaturalesontogenyOtaria byroniasexual dimorphismSouth American sea liontympanic bullaHere we describe and explore for the first time the ontogeny and sexual dimorphism of the auditory region of <i>Otaria byronia</i>. We studied the tympanic region of skulls of 237 specimens of different ages and sexes. Geometric morphometric methods were used to analyze the tympanic bulla. In addition, 3D reconstructions of the tympanic bulla were performed using computed tomography analysis scans and a serial wearing technique. We provide a description of the external and internal morphology of the tympanic bulla in both sexes and across different stages (bioclasses). The average shape of the bulla in <i>O. byronia</i> has a subtriangular contour, with variations between sexes and ages. Each stage (bioclasses I, II, and III) is characterized by the respective mean shape of the tympanic bulla and designated as a morphoclass (1, 2, and 3). In all cases, the ectotympanic shows greater surface area than the endotympanic, as in other otariids, in contrast to Phocidae. During ontogeny, the relative size of the ectotympanic increases, growing in all directions and covering the endotympanic. This pattern is seen to the greatest extent in adult males, in which the ectotympanic forms an extremely well-developed apophysis jugulare. No differences in internal morphology of the tympanic cavity were recorded between ages and sexes. The bulla does not increase in thickness in successive age classes; in fact, the walls are extremely thin in the adult stages, despite the extensive development of its processes. This pattern is opposite that observed in Phocidae. In morphoclass 3, adult males older than 7 years undergo hypermorphic change that results in a peramorphic condition when compared to adult females. These changes probably follow the same pattern shown by the rest of the skull and contribute to the marked sexual dimorphism of the species.Facultad de Ciencias Naturales y Museo2018-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf54-71http://sedici.unlp.edu.ar/handle/10915/127129enginfo:eu-repo/semantics/altIdentifier/issn/1469-7580info:eu-repo/semantics/altIdentifier/issn/0021-8782info:eu-repo/semantics/altIdentifier/pmid/29082536info:eu-repo/semantics/altIdentifier/doi/10.1111/joa.12717info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-03T11:02:48Zoai:sedici.unlp.edu.ar:10915/127129Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-03 11:02:48.65SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
title |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
spellingShingle |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism Loza, Cleopatra Mara Ciencias Naturales ontogeny Otaria byronia sexual dimorphism South American sea lion tympanic bulla |
title_short |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
title_full |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
title_fullStr |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
title_full_unstemmed |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
title_sort |
The tympanic region of <i>Otaria byronia</i> (Otariidae, Carnivora) – morphology, ontogeny, age classes and dimorphism |
dc.creator.none.fl_str_mv |
Loza, Cleopatra Mara Scarano, Alejo Carlos Galliari, Fernando Carlos Soibelzon, Leopoldo Héctor Negrete, Javier Carlini, Alfredo Armando |
author |
Loza, Cleopatra Mara |
author_facet |
Loza, Cleopatra Mara Scarano, Alejo Carlos Galliari, Fernando Carlos Soibelzon, Leopoldo Héctor Negrete, Javier Carlini, Alfredo Armando |
author_role |
author |
author2 |
Scarano, Alejo Carlos Galliari, Fernando Carlos Soibelzon, Leopoldo Héctor Negrete, Javier Carlini, Alfredo Armando |
author2_role |
author author author author author |
dc.subject.none.fl_str_mv |
Ciencias Naturales ontogeny Otaria byronia sexual dimorphism South American sea lion tympanic bulla |
topic |
Ciencias Naturales ontogeny Otaria byronia sexual dimorphism South American sea lion tympanic bulla |
dc.description.none.fl_txt_mv |
Here we describe and explore for the first time the ontogeny and sexual dimorphism of the auditory region of <i>Otaria byronia</i>. We studied the tympanic region of skulls of 237 specimens of different ages and sexes. Geometric morphometric methods were used to analyze the tympanic bulla. In addition, 3D reconstructions of the tympanic bulla were performed using computed tomography analysis scans and a serial wearing technique. We provide a description of the external and internal morphology of the tympanic bulla in both sexes and across different stages (bioclasses). The average shape of the bulla in <i>O. byronia</i> has a subtriangular contour, with variations between sexes and ages. Each stage (bioclasses I, II, and III) is characterized by the respective mean shape of the tympanic bulla and designated as a morphoclass (1, 2, and 3). In all cases, the ectotympanic shows greater surface area than the endotympanic, as in other otariids, in contrast to Phocidae. During ontogeny, the relative size of the ectotympanic increases, growing in all directions and covering the endotympanic. This pattern is seen to the greatest extent in adult males, in which the ectotympanic forms an extremely well-developed apophysis jugulare. No differences in internal morphology of the tympanic cavity were recorded between ages and sexes. The bulla does not increase in thickness in successive age classes; in fact, the walls are extremely thin in the adult stages, despite the extensive development of its processes. This pattern is opposite that observed in Phocidae. In morphoclass 3, adult males older than 7 years undergo hypermorphic change that results in a peramorphic condition when compared to adult females. These changes probably follow the same pattern shown by the rest of the skull and contribute to the marked sexual dimorphism of the species. Facultad de Ciencias Naturales y Museo |
description |
Here we describe and explore for the first time the ontogeny and sexual dimorphism of the auditory region of <i>Otaria byronia</i>. We studied the tympanic region of skulls of 237 specimens of different ages and sexes. Geometric morphometric methods were used to analyze the tympanic bulla. In addition, 3D reconstructions of the tympanic bulla were performed using computed tomography analysis scans and a serial wearing technique. We provide a description of the external and internal morphology of the tympanic bulla in both sexes and across different stages (bioclasses). The average shape of the bulla in <i>O. byronia</i> has a subtriangular contour, with variations between sexes and ages. Each stage (bioclasses I, II, and III) is characterized by the respective mean shape of the tympanic bulla and designated as a morphoclass (1, 2, and 3). In all cases, the ectotympanic shows greater surface area than the endotympanic, as in other otariids, in contrast to Phocidae. During ontogeny, the relative size of the ectotympanic increases, growing in all directions and covering the endotympanic. This pattern is seen to the greatest extent in adult males, in which the ectotympanic forms an extremely well-developed apophysis jugulare. No differences in internal morphology of the tympanic cavity were recorded between ages and sexes. The bulla does not increase in thickness in successive age classes; in fact, the walls are extremely thin in the adult stages, despite the extensive development of its processes. This pattern is opposite that observed in Phocidae. In morphoclass 3, adult males older than 7 years undergo hypermorphic change that results in a peramorphic condition when compared to adult females. These changes probably follow the same pattern shown by the rest of the skull and contribute to the marked sexual dimorphism of the species. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-01 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Articulo http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
format |
article |
status_str |
publishedVersion |
dc.identifier.none.fl_str_mv |
http://sedici.unlp.edu.ar/handle/10915/127129 |
url |
http://sedici.unlp.edu.ar/handle/10915/127129 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/issn/1469-7580 info:eu-repo/semantics/altIdentifier/issn/0021-8782 info:eu-repo/semantics/altIdentifier/pmid/29082536 info:eu-repo/semantics/altIdentifier/doi/10.1111/joa.12717 |
dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
eu_rights_str_mv |
openAccess |
rights_invalid_str_mv |
http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
dc.format.none.fl_str_mv |
application/pdf 54-71 |
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