The role of evolutionary integration in the morphological evolution of the skull of caviomorph rodents (Rodentia: Hystricomorpha)

The mammalian cranium is a complex structure composed by three partially independent modules: face, cranial base and cranial vault. At the same time, it interacts with the mandible by sharing the masticatory function. Since these units develop and work together, their function and evolution may occu...

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Detalles Bibliográficos
Autores: Alvarez, Alicia, Perez, Sergio Ivan, Verzi, Diego Hector
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/46003
Acceso en línea:http://hdl.handle.net/11336/46003
Access Level:acceso abierto
Palabra clave:Caviomorph Rodents
Evolutionary Allometry
Geometric Morphometrics
Morphological Integration
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:The mammalian cranium is a complex structure composed by three partially independent modules: face, cranial base and cranial vault. At the same time, it interacts with the mandible by sharing the masticatory function. Since these units develop and work together, their function and evolution may occur through correlated changes. Here, we assessed the patterns of evolutionary shape variation and covariation (i.e. integration) of cranial modules and mandible among the highly ecomorphologically diverse caviomorph rodents, and the potential evolutionary consequences on the morphological evolution of this clade. Threedimensional geometric morphometrics was used to describe cranio-mandibular shape. The phylogenetic signal and evolutionary allometric component of morphometric variables were analyzed; in addition, evolutionary covariation among cranial modules and mandible was assessed using phylogenetic comparative methods. Significant phylogenetic signal and evolutionary allometry were detected. Large covariance values, involving coordinated breadth increase as the main shape change, were recorded between cranial vault and base, followed by cranial vault and face, and face and mandible. Since the basicraniummay be the main cranial integrator, the overall widening of the cranial base, derived from the enlargement of the auditory bullae, could be influencing the integrated evolution of skull. In caviomorphs, the craniomandibular morphological evolution would be the outcome of a tight covariation among the modular units, and this could be driven by several factors such as allometry and specializations<br />to environmental niches.