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A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)

Authoritative anatomical references depict domestic dogs and cats as having a malleus with a short rostral (anterior) process that is connected via a ligament to the ectotympanic of the auditory bulla. Similar mallei have been reported for representatives of each of the 15 extant families of Carnivo...

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Autores principales: Wible, John R., Spaulding, Michelle
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3507746/
https://www.ncbi.nlm.nih.gov/pubmed/23209753
http://dx.doi.org/10.1371/journal.pone.0050485
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author Wible, John R.
Spaulding, Michelle
author_facet Wible, John R.
Spaulding, Michelle
author_sort Wible, John R.
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description Authoritative anatomical references depict domestic dogs and cats as having a malleus with a short rostral (anterior) process that is connected via a ligament to the ectotympanic of the auditory bulla. Similar mallei have been reported for representatives of each of the 15 extant families of Carnivora, the placental order containing dogs and cats. This morphology is in contrast to a malleus with a long rostral process anchored to the ectotympanic that is considered to be primitive for mammals. Our reexamination of extant carnivorans found representatives from 12 families that possess an elongate rostral process anchored to the ectotympanic. Consequently, the malleus also is a component of the bulla. In a subset of our carnivoran sample, we confirmed that the elongate rostral process on the ectotympanic is continuous with the rest of the malleus through a thin osseous lamina. This morphology is reconstructed as primitive for Carnivora. Prior inaccurate descriptions of the taxa in our sample having mallei continuous with the bulla were based on damaged mallei. In addition to coupling to the ectotympanic, the rostral process of the malleus was found to have a hook-like process that fits in a facet on the skull base in representatives from seven families (felids, nandiniids, viverrids, canids, ursids, procyonids, and mustelids); its occurrence in the remaining families could not be ascertained. This feature is named herein the mallear hook and is likewise reconstructed to be primitive for Carnivora. We also investigated mallei in one additional placental order reported to have mallei not connected to the ectotympanic, Pholidota (pangolins), the extant sister group of Carnivora. We found pholidotans to also have anchored mallei with long rostral processes, but lacking mallear hooks. In light of our results, other mammals previously reported to have short rostral processes should be reexamined.
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spelling pubmed-35077462012-12-03 A Reexamination of the Carnivora Malleus (Mammalia, Placentalia) Wible, John R. Spaulding, Michelle PLoS One Research Article Authoritative anatomical references depict domestic dogs and cats as having a malleus with a short rostral (anterior) process that is connected via a ligament to the ectotympanic of the auditory bulla. Similar mallei have been reported for representatives of each of the 15 extant families of Carnivora, the placental order containing dogs and cats. This morphology is in contrast to a malleus with a long rostral process anchored to the ectotympanic that is considered to be primitive for mammals. Our reexamination of extant carnivorans found representatives from 12 families that possess an elongate rostral process anchored to the ectotympanic. Consequently, the malleus also is a component of the bulla. In a subset of our carnivoran sample, we confirmed that the elongate rostral process on the ectotympanic is continuous with the rest of the malleus through a thin osseous lamina. This morphology is reconstructed as primitive for Carnivora. Prior inaccurate descriptions of the taxa in our sample having mallei continuous with the bulla were based on damaged mallei. In addition to coupling to the ectotympanic, the rostral process of the malleus was found to have a hook-like process that fits in a facet on the skull base in representatives from seven families (felids, nandiniids, viverrids, canids, ursids, procyonids, and mustelids); its occurrence in the remaining families could not be ascertained. This feature is named herein the mallear hook and is likewise reconstructed to be primitive for Carnivora. We also investigated mallei in one additional placental order reported to have mallei not connected to the ectotympanic, Pholidota (pangolins), the extant sister group of Carnivora. We found pholidotans to also have anchored mallei with long rostral processes, but lacking mallear hooks. In light of our results, other mammals previously reported to have short rostral processes should be reexamined. Public Library of Science 2012-11-27 /pmc/articles/PMC3507746/ /pubmed/23209753 http://dx.doi.org/10.1371/journal.pone.0050485 Text en © 2012 Wible, Spaulding http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Wible, John R.
Spaulding, Michelle
A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)
title A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)
title_full A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)
title_fullStr A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)
title_full_unstemmed A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)
title_short A Reexamination of the Carnivora Malleus (Mammalia, Placentalia)
title_sort reexamination of the carnivora malleus (mammalia, placentalia)
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3507746/
https://www.ncbi.nlm.nih.gov/pubmed/23209753
http://dx.doi.org/10.1371/journal.pone.0050485
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