Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte

Autores
Soibelzon, Leopoldo Héctor
Año de publicación
2000
Idioma
español castellano
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The subfamily Tremarctinae (Ursidae: Camivora), distributed exclusively in America, comprises five genera: Plionarctos from the upper Pliocene of North America, Arctodus, that groups the two North American species; Arctotherium and Pararctotherium with an uncertain number of South American species; and Tremarctos with one fossil species in North America and a living one in South America. One of the characters usually taken into account in the definition of the subfamily Tremarctinae is the premasseteric fossa in the lateral outer side of the mandible body, which occupies almost all the thickness of the mandibular body. This description agrees with the observations in Tremarctos and Arctodus, but in the Argentine and Bolivian species of Arctotherium and Pararctotherium this fossa is extremely reduced or absent. In order to compare the premasseteric fossa of Tremarctos and Arctodus with that of the South American fossil genera, it was measured the volume of this fossa and related with the thickness of the mandibular ramus, between the second and third lower molar. The results show the great difference of the structure between Tremarctos and Arctodus on one side, and Arctotherium and Pararctotherium, on the other. lt is proposed that in the South American genera the premasseteric fossa is drastically reduced, disappearing in some cases. This may be considered a derived character for the group Arctotherium-Pararctotherium. Consequently, the opinion of some authors who include all the extinct genera of South American 'bears as subgenera of the genus Arctodus would be invalidated.
Museo de La Plata
Materia
Paleontología
Ciencias Naturales
América del Sur; América del Norte
oso
Tremarctinae; fosa premasetérica
Filogenia
Ursidae
Tremarctinae, premasseteric fossa
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc/3.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/5369
Acceder
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oai_identifier_str oai:sedici.unlp.edu.ar:10915/5369
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network_name_str SEDICI (UNLP)
spelling Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del NorteNew evidence on the filogenetic relationship betwen South and North American Pleistocene bearsSoibelzon, Leopoldo HéctorPaleontologíaCiencias NaturalesAmérica del Sur; América del NorteosoTremarctinae; fosa premasetéricaFilogeniaUrsidaeTremarctinae, premasseteric fossaThe subfamily Tremarctinae (Ursidae: Camivora), distributed exclusively in America, comprises five genera: Plionarctos from the upper Pliocene of North America, Arctodus, that groups the two North American species; Arctotherium and Pararctotherium with an uncertain number of South American species; and Tremarctos with one fossil species in North America and a living one in South America. One of the characters usually taken into account in the definition of the subfamily Tremarctinae is the premasseteric fossa in the lateral outer side of the mandible body, which occupies almost all the thickness of the mandibular body. This description agrees with the observations in Tremarctos and Arctodus, but in the Argentine and Bolivian species of Arctotherium and Pararctotherium this fossa is extremely reduced or absent. In order to compare the premasseteric fossa of Tremarctos and Arctodus with that of the South American fossil genera, it was measured the volume of this fossa and related with the thickness of the mandibular ramus, between the second and third lower molar. The results show the great difference of the structure between Tremarctos and Arctodus on one side, and Arctotherium and Pararctotherium, on the other. lt is proposed that in the South American genera the premasseteric fossa is drastically reduced, disappearing in some cases. This may be considered a derived character for the group Arctotherium-Pararctotherium. Consequently, the opinion of some authors who include all the extinct genera of South American 'bears as subgenera of the genus Arctodus would be invalidated.Museo de La Plata2000info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf45-50http://sedici.unlp.edu.ar/handle/10915/5369spainfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc/3.0/Creative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-03T10:22:26Zoai:sedici.unlp.edu.ar:10915/5369Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-03 10:22:27.295SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
New evidence on the filogenetic relationship betwen South and North American Pleistocene bears
title Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
spellingShingle Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
Soibelzon, Leopoldo Héctor
Paleontología
Ciencias Naturales
América del Sur; América del Norte
oso
Tremarctinae; fosa premasetérica
Filogenia
Ursidae
Tremarctinae, premasseteric fossa
title_short Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
title_full Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
title_fullStr Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
title_full_unstemmed Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
title_sort Nueva evidencia sobre la relación filogenética entre los osos pleistocenos de América del Sur y del Norte
dc.creator.none.fl_str_mv Soibelzon, Leopoldo Héctor
author Soibelzon, Leopoldo Héctor
author_facet Soibelzon, Leopoldo Héctor
author_role author
dc.subject.none.fl_str_mv Paleontología
Ciencias Naturales
América del Sur; América del Norte
oso
Tremarctinae; fosa premasetérica
Filogenia
Ursidae
Tremarctinae, premasseteric fossa
topic Paleontología
Ciencias Naturales
América del Sur; América del Norte
oso
Tremarctinae; fosa premasetérica
Filogenia
Ursidae
Tremarctinae, premasseteric fossa
dc.description.none.fl_txt_mv The subfamily Tremarctinae (Ursidae: Camivora), distributed exclusively in America, comprises five genera: Plionarctos from the upper Pliocene of North America, Arctodus, that groups the two North American species; Arctotherium and Pararctotherium with an uncertain number of South American species; and Tremarctos with one fossil species in North America and a living one in South America. One of the characters usually taken into account in the definition of the subfamily Tremarctinae is the premasseteric fossa in the lateral outer side of the mandible body, which occupies almost all the thickness of the mandibular body. This description agrees with the observations in Tremarctos and Arctodus, but in the Argentine and Bolivian species of Arctotherium and Pararctotherium this fossa is extremely reduced or absent. In order to compare the premasseteric fossa of Tremarctos and Arctodus with that of the South American fossil genera, it was measured the volume of this fossa and related with the thickness of the mandibular ramus, between the second and third lower molar. The results show the great difference of the structure between Tremarctos and Arctodus on one side, and Arctotherium and Pararctotherium, on the other. lt is proposed that in the South American genera the premasseteric fossa is drastically reduced, disappearing in some cases. This may be considered a derived character for the group Arctotherium-Pararctotherium. Consequently, the opinion of some authors who include all the extinct genera of South American 'bears as subgenera of the genus Arctodus would be invalidated.
Museo de La Plata
description The subfamily Tremarctinae (Ursidae: Camivora), distributed exclusively in America, comprises five genera: Plionarctos from the upper Pliocene of North America, Arctodus, that groups the two North American species; Arctotherium and Pararctotherium with an uncertain number of South American species; and Tremarctos with one fossil species in North America and a living one in South America. One of the characters usually taken into account in the definition of the subfamily Tremarctinae is the premasseteric fossa in the lateral outer side of the mandible body, which occupies almost all the thickness of the mandibular body. This description agrees with the observations in Tremarctos and Arctodus, but in the Argentine and Bolivian species of Arctotherium and Pararctotherium this fossa is extremely reduced or absent. In order to compare the premasseteric fossa of Tremarctos and Arctodus with that of the South American fossil genera, it was measured the volume of this fossa and related with the thickness of the mandibular ramus, between the second and third lower molar. The results show the great difference of the structure between Tremarctos and Arctodus on one side, and Arctotherium and Pararctotherium, on the other. lt is proposed that in the South American genera the premasseteric fossa is drastically reduced, disappearing in some cases. This may be considered a derived character for the group Arctotherium-Pararctotherium. Consequently, the opinion of some authors who include all the extinct genera of South American 'bears as subgenera of the genus Arctodus would be invalidated.
publishDate 2000
dc.date.none.fl_str_mv 2000
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
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dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/5369
url http://sedici.unlp.edu.ar/handle/10915/5369
dc.language.none.fl_str_mv spa
language spa
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
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eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc/3.0/
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