Timing of ontogenetic changes of two cranial regions in Sotalia guianensis (Delphinidae)

Autor(es)

Sydney, Nicolle V. ^[1] ; Machado, Fabio A. ^[2] ; Hingst-Zaher, Erika ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Parana, Programa Posgrad Zool, BR-81531970 Curitiba, Parana - Brazil

^[2] Univ Sao Paulo, Inst Biociencias USP, Programa Posgrad Zool, BR-05508900 Sao Paulo - Brazil

^[3] Inst Butantan, Museu Biol, BR-05503900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Mammalian Biology; v. 77, n. 6, p. 397-403, 2012.
• Citações Web of Science: 9

Resumo

Despite the fact that heterochronic processes seem to be an important process determining morphological evolution of the delphinid skull, previous workers have not found allometric scaling as relevant factor in the differentiation within the genus Sotalia. Here we analyzed the skull ontogeny of the estuarine dolphin S. guianensis and investigate differential growth and shape changes of two cranial regions the neurocranium and the face in order to evaluate the relevance of cranial compartmentalization on the ontogeny of this structure. Our results show that, even though both cranial regions stop growing at adulthood, the face has higher initial growth rates than the neurocranium. The rate of shape changes is also different for both regions, with the face showing a initially higher, but rapidly decreasing rate of change, while the neurocranium shows a slow decreasing rate, leading to persistent and localized shape changes throughout adult life, a pattern that could be related to epigenetic regional factors. The pattern of ontogenetic shape change described here is similar to those described for other groups of Delphinidae and also match intra and interspecific variation found within the family, suggesting that mosaic heterochrony could be an important factor in the morphological evolution of this group. (C) 2012 Deutsche Gesellschaft fur Saugetierkunde. Published by Elsevier GmbH. All rights reserved. (AU)

• Processo FAPESP: 07/52144-5 - Análise da variação longitudinal do esqueleto axial em serpentes (Squamata) empregando ferramentas de morfometria geométrica
• Beneficiário: Fábio de Andrade Machado
• Modalidade de apoio: Bolsas no Brasil - Mestrado