Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution

Echimyidae constitute the most important radiation of caviomorph rodents in the Neotropical region, represented by 20 extant genera and several extinct species. Both in extant and fossil forms, this diversity is reflected by a significant morphological variation found in crown structures of the chee...

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Autores principales: Candela, Adriana Magdalena, Rasia, Luciano Luis
Formato: Articulo
Lenguaje:Inglés
Publicado: 2012
Materias:
Paleontología
Argentina
cheek teeth characters
dental evolution
Late Cenozoic
Myocastorinae
parsimony analysis
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84125
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-84125
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Paleontología
Argentina
cheek teeth characters
dental evolution
Late Cenozoic
Myocastorinae
parsimony analysis
spellingShingle Paleontología
Argentina
cheek teeth characters
dental evolution
Late Cenozoic
Myocastorinae
parsimony analysis
Candela, Adriana Magdalena
Rasia, Luciano Luis
Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution
topic_facet Paleontología
Argentina
cheek teeth characters
dental evolution
Late Cenozoic
Myocastorinae
parsimony analysis
description Echimyidae constitute the most important radiation of caviomorph rodents in the Neotropical region, represented by 20 extant genera and several extinct species. Both in extant and fossil forms, this diversity is reflected by a significant morphological variation found in crown structures of the cheek teeth. Different hypotheses of primary homology have been proposed for these structures, which, in turn, support diverse dental evolutionary hypotheses. In this contribution we inspect the main structures (cusps and lophids) of the lower deciduous teeth and molars in extinct and extant Echimyidae, and establish their topological correspondences. Comparisons with cusps and lophids of Erethizontidae are emphasized. We explore the testing of alternative primary hypotheses of lophid correspondences in a cladistic context. Following a 'dynamic' approach, we select the hypothesis of primary homology, which produced the more parsimonious results, and evaluate the evolutionary transformations of the dental characters analysed. In this context, the phylogenetic relationships of living Myocastor coypus (Molina, 1782) with the extinct Tramyocastor and Paramyocastor are tested. Our results indicate that pentalophodonty is the derived condition for the lower molars in Echimyidae, that trilophodonty evolved independently at least three times during the evolutionary history of these rodents, and that tetralophodonty represents the plesiomorphic condition. This study shows that dental evolution in echimyids can be better understood when occlusal structures are expressed as reliably comparable characters, and when fossils are taken into account.
format Articulo
Articulo
author Candela, Adriana Magdalena
Rasia, Luciano Luis
author_facet Candela, Adriana Magdalena
Rasia, Luciano Luis
author_sort Candela, Adriana Magdalena
title Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution
title_short Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution
title_full Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution
title_fullStr Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution
title_full_unstemmed Tooth morphology of Echimyidae (Rodentia, Caviomorpha): homology assessments, fossils, and evolution
title_sort tooth morphology of echimyidae (rodentia, caviomorpha): homology assessments, fossils, and evolution
publishDate 2012
url http://sedici.unlp.edu.ar/handle/10915/84125
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AT rasialucianoluis toothmorphologyofechimyidaerodentiacaviomorphahomologyassessmentsfossilsandevolution
bdutipo_str Repositorios
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