MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM”
South American native ungulates include several extinct lineages that evolved within the context of South American Cenozoic geographic isolation. By the late early Miocene Santacrucian Age, the orders Notoungulata, Litopterna, and Astrapotheria were differentiated. Recent ecomorphological studies hi...
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| Format: | Article |
| Language: | English |
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Asociación Paleontológica Argentina
2017-12-01
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| Series: | Publicación Electrónica de la Asociación Paleontológica Argentina |
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| Online Access: | http://www.peapaleontologica.org.ar/index.php/peapa/article/view/253 |
| _version_ | 1811215260013559808 |
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| author | Cassini, Guillermo H. Muñoz, nahuel A. Vizcaíno, Sergio F. |
| author_facet | Cassini, Guillermo H. Muñoz, nahuel A. Vizcaíno, Sergio F. |
| author_sort | Cassini, Guillermo H. |
| collection | DOAJ |
| description | South American native ungulates include several extinct lineages that evolved within the context of South American Cenozoic geographic isolation. By the late early Miocene Santacrucian Age, the orders Notoungulata, Litopterna, and Astrapotheria were differentiated. Recent ecomorphological studies highlighted complex functional patterns between their habitat/diet and hypsodonty. In order to understand these relationships in an evolutionary context we used geometric morphometrics methods (27 3-D landmarks) to evaluate the morphological integration of two of the primary functional units of the mandible: the alveolar region and the ascending ramus. Principal component analyses (PCA) and two blocks Partial Least Squares analyses (PLS) were used to explore the patterns of variation and covariation between these two modules. The main variation in shape is related to the robusticity and curvature of the mandibular corpus, and the relative size of the angular and coronoid process. The PLS analyses show a very strong morphological integration within the Litopterna, but a pattern of modularity in the Notoungulata. There is a common pattern of covariation in Astrapotheria and Litopterna, which might be due to similar constraints. The different covariation patterns in notoungulates with respect to litopterns are in concordance with both the taxonomic and morphological diversity of the clades, particularly in the typotheres. The modularity present in notoungulates could have allowed specializations in each module of the mandible, related to crown height or muscle attachments, without a high morphological constrain. This could have resulted in their high morphological diversity, in contrast with the more conservative morphology present in litopterns. |
| first_indexed | 2024-04-12T06:18:30Z |
| format | Article |
| id | doaj.art-b6ad52f7f8fb46679f1fd7e8fdcef5ad |
| institution | Directory Open Access Journal |
| issn | 2469-0228 |
| language | English |
| last_indexed | 2024-04-12T06:18:30Z |
| publishDate | 2017-12-01 |
| publisher | Asociación Paleontológica Argentina |
| record_format | Article |
| series | Publicación Electrónica de la Asociación Paleontológica Argentina |
| spelling | doaj.art-b6ad52f7f8fb46679f1fd7e8fdcef5ad2022-12-22T03:44:23ZengAsociación Paleontológica ArgentinaPublicación Electrónica de la Asociación Paleontológica Argentina2469-02282017-12-011725874doi:10.5710/PEAPA.18.12.2017.253MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM”Cassini, Guillermo H.0Muñoz, nahuel A.1Vizcaíno, Sergio F.2División Mastozoología, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Av. Ángel Gallardo 470, Ciudad Autónoma de Buenos Aires, C1405DJR, ArgentinaDivisión Paleontología Vertebrados, Museo de La Plata, Unidades de Investigación Anexo Museo, FCNyM-UNLP, 60 y 122, 1900 La Plata, Argentina. División Paleontología Vertebrados, Museo de La Plata, Unidades de Investigación Anexo Museo, FCNyM-UNLP, 60 y 122, 1900 La Plata, Argentina. South American native ungulates include several extinct lineages that evolved within the context of South American Cenozoic geographic isolation. By the late early Miocene Santacrucian Age, the orders Notoungulata, Litopterna, and Astrapotheria were differentiated. Recent ecomorphological studies highlighted complex functional patterns between their habitat/diet and hypsodonty. In order to understand these relationships in an evolutionary context we used geometric morphometrics methods (27 3-D landmarks) to evaluate the morphological integration of two of the primary functional units of the mandible: the alveolar region and the ascending ramus. Principal component analyses (PCA) and two blocks Partial Least Squares analyses (PLS) were used to explore the patterns of variation and covariation between these two modules. The main variation in shape is related to the robusticity and curvature of the mandibular corpus, and the relative size of the angular and coronoid process. The PLS analyses show a very strong morphological integration within the Litopterna, but a pattern of modularity in the Notoungulata. There is a common pattern of covariation in Astrapotheria and Litopterna, which might be due to similar constraints. The different covariation patterns in notoungulates with respect to litopterns are in concordance with both the taxonomic and morphological diversity of the clades, particularly in the typotheres. The modularity present in notoungulates could have allowed specializations in each module of the mandible, related to crown height or muscle attachments, without a high morphological constrain. This could have resulted in their high morphological diversity, in contrast with the more conservative morphology present in litopterns.http://www.peapaleontologica.org.ar/index.php/peapa/article/view/253NotoungulataLitopternaSantacrucianGeometric morphometrics |
| spellingShingle | Cassini, Guillermo H. Muñoz, nahuel A. Vizcaíno, Sergio F. MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM” Publicación Electrónica de la Asociación Paleontológica Argentina Notoungulata Litopterna Santacrucian Geometric morphometrics |
| title | MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM” |
| title_full | MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM” |
| title_fullStr | MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM” |
| title_full_unstemmed | MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM” |
| title_short | MORPHOLOGICAL INTEGRATION OF NATIVE SOUTH AMERICAN UNGULATE MANDIBLES. A TRIBUTE TO D’ARCY THOMPSON IN THE CENTENNIAL OF “ON GROWTH AND FORM” |
| title_sort | morphological integration of native south american ungulate mandibles a tribute to d arcy thompson in the centennial of on growth and form |
| topic | Notoungulata Litopterna Santacrucian Geometric morphometrics |
| url | http://www.peapaleontologica.org.ar/index.php/peapa/article/view/253 |
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