Artículo
Unexpected skeletal histology of an ichthyosaur from the middle jurassic of patagonia: Implications for evolution of bone microstructure among secondary aquatic tetrapods
Fecha de publicación:
03/2012
Editorial:
Springer
Revista:
Naturwissenschaften
ISSN:
0028-1042
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
During the Mesozoic, one of the most significant evolutionary processes was the secondary adaptation of tetrapods to life in water. Several non-related lineages invaded from the terrestrial realms and from the oceans of the entire world. Among these lineages, ichthyosaurs were particularly successful. Advance parvipelvian ichthyosaurs were the first tetrapods to evolve a fish-shaped body profile. The deep skeletal modifications of their bodies, as well as their biology, depict advance ichthyosaurs as the paradigm of secondary adaptation of reptiles tomarine life. Functional inferences point to themas off-shore cruising forms, similar to a living tuna, and some of them were capable of deep diving. Bone histology of some genera such as Temnodontosaurus, Stenopterygius, Ichthyosaurus, and Caypullisaurus, characterized by overall cancellous bone, is consistent with the idea of a fish-shaped ichthyosaurs as fast and far cruisers. Here, we provide histological examination of the ribs of the Middle Jurassic parvipelvian Mollesaurus. Contrasting with the bone histology of other parvipelvian, Mollesaurus ribs are characterized by a compact and thick cortex. Our data indicate that the rib cage was heavy and suggest that not all advanced ichthyosaurs were fast cruisers. The compact and dense ribs in these parvipelvian show that advance ichthyosaurs were ecologically more diverse than previously thought and that the lightening of the skeleton reversed, as also occurred in the evolution of cetacean, at least once along the evolutionary history of ichthyosaurs.
Palabras clave:
BONE HISTOLOGY
,
ICHTHYOSAURS
,
MIDDLE JURASSIC
,
MOLLESAURUS
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(CCT - LA PLATA)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - LA PLATA
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - LA PLATA
Articulos(CCT - PATAGONIA NORTE)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - PATAGONIA NORTE
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - PATAGONIA NORTE
Citación
Talevi, Marianella; Fernández, Marta Susana; Unexpected skeletal histology of an ichthyosaur from the middle jurassic of patagonia: Implications for evolution of bone microstructure among secondary aquatic tetrapods; Springer; Naturwissenschaften; 99; 3; 3-2012; 241-244
Compartir
Altmétricas