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A dwarf walrus from the Miocene of Baja California Sur, Mexico
Here, we describe the odobenid Nanodobenus arandai gen. et sp. nov., based on a nearly complete left mandible from the mid to late Miocene Tortugas Formation in Baja California Sur. Nanodobenus is distinguished among odobenids by displaying a unique combination of plesiomorphic and derived character...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society Publishing
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124023/ https://www.ncbi.nlm.nih.gov/pubmed/30225030 http://dx.doi.org/10.1098/rsos.180423 |
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author | Velez-Juarbe, Jorge Salinas-Márquez, Fernando M. |
author_facet | Velez-Juarbe, Jorge Salinas-Márquez, Fernando M. |
author_sort | Velez-Juarbe, Jorge |
collection | PubMed |
description | Here, we describe the odobenid Nanodobenus arandai gen. et sp. nov., based on a nearly complete left mandible from the mid to late Miocene Tortugas Formation in Baja California Sur. Nanodobenus is distinguished among odobenids by displaying a unique combination of plesiomorphic and derived characters, such as narrow mandibular symphysis, well-developed genial tuberosity, bilobed canine and p2 roots, bulbous post-canine teeth with the paraconid, protoconid and hypoconid, and smooth lingual cingula. Moreover, it is characterized by its small adult body length, which is estimated at about 1.65 m. Throughout the Miocene–Pliocene odobenids are characterized by an increase in body size, especially after the extinction of desmatophocids in the late Miocene. The small size of Nanodobenus departs from this trend, demonstrating that there was greater size disparity among odobenids in the mid–late Miocene than previously thought. It is hypothesized that Nanodobenus occupied a niche that was later on occupied by similar-sized otariids, such as Thalassoleon mexicanus, which occurs sympatrically with large odobenids in the overlying Almejas Formation. |
format | Online Article Text |
id | pubmed-6124023 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | The Royal Society Publishing |
record_format | MEDLINE/PubMed |
spelling | pubmed-61240232018-09-17 A dwarf walrus from the Miocene of Baja California Sur, Mexico Velez-Juarbe, Jorge Salinas-Márquez, Fernando M. R Soc Open Sci Biology (Whole Organism) Here, we describe the odobenid Nanodobenus arandai gen. et sp. nov., based on a nearly complete left mandible from the mid to late Miocene Tortugas Formation in Baja California Sur. Nanodobenus is distinguished among odobenids by displaying a unique combination of plesiomorphic and derived characters, such as narrow mandibular symphysis, well-developed genial tuberosity, bilobed canine and p2 roots, bulbous post-canine teeth with the paraconid, protoconid and hypoconid, and smooth lingual cingula. Moreover, it is characterized by its small adult body length, which is estimated at about 1.65 m. Throughout the Miocene–Pliocene odobenids are characterized by an increase in body size, especially after the extinction of desmatophocids in the late Miocene. The small size of Nanodobenus departs from this trend, demonstrating that there was greater size disparity among odobenids in the mid–late Miocene than previously thought. It is hypothesized that Nanodobenus occupied a niche that was later on occupied by similar-sized otariids, such as Thalassoleon mexicanus, which occurs sympatrically with large odobenids in the overlying Almejas Formation. The Royal Society Publishing 2018-08-08 /pmc/articles/PMC6124023/ /pubmed/30225030 http://dx.doi.org/10.1098/rsos.180423 Text en © 2018 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. |
spellingShingle | Biology (Whole Organism) Velez-Juarbe, Jorge Salinas-Márquez, Fernando M. A dwarf walrus from the Miocene of Baja California Sur, Mexico |
title | A dwarf walrus from the Miocene of Baja California Sur, Mexico |
title_full | A dwarf walrus from the Miocene of Baja California Sur, Mexico |
title_fullStr | A dwarf walrus from the Miocene of Baja California Sur, Mexico |
title_full_unstemmed | A dwarf walrus from the Miocene of Baja California Sur, Mexico |
title_short | A dwarf walrus from the Miocene of Baja California Sur, Mexico |
title_sort | dwarf walrus from the miocene of baja california sur, mexico |
topic | Biology (Whole Organism) |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124023/ https://www.ncbi.nlm.nih.gov/pubmed/30225030 http://dx.doi.org/10.1098/rsos.180423 |
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