Analizando los patrones ontogenéticos del paladar de los cocodrilos en el 22nd European Congress of Herpetology

Durante el 22nd European Congress of Herpetology, celebrado en Wolverhampton (UK) del 4-8 septiembre, Ane de Celis presentó también la comunicación oral “A geometric morphometric approach to palatal ontogeny in Crocodylia”. En este trabajo se analizó cómo varía la morfología del paladar de las especies actuales de cocodrilo desde que nacen hasta que alcanzan el estadío adulto, además de analizar los cambios de ocupación del morfoespacio, la disparidad y reconstruir las trayectorias ontogenéticas de todas estas especies de cocodrilo actuales. Los resultados muestran que incluso los individuos juveniles de aligatóridos y crocodílidos tienen morfologías palatales claramente diferentes, ocupan distintos morfoespacios desde el estadío juvenil en adelante, y que unas pocas especies de cocodrilo muestran trayectorias ontogenéticas distintas a las del resto. El resumen del trabajo a continuación:

During the development and growth process of an animal, it is often observed that different anatomical structures undergo changes in their morphology and relative proportions in a phenomenon known as ontogenetic allometry. In extant crocodylians, their ontogenetic cranial series show an increase in the relative size of the rostral versus postrostral region of the cranium, and changes in the relative size of the orbits, and the shape of the cranial table, among many others. These morphological changes in the dorsal aspect of the cranium are widespread and well documented in the ontogenetic series of most crocodylians. However, the ontogenetic changes that occur in the palate have not been thoroughly characterised and analysed in most crocodylian species. Therefore, the ontogeny of the crocodylian palate was analysed using 2D geometric morphometrics on a sample of 334 craniums from 23 species, ranging from hatchling to adult individual specimens. The morphological changes that occur in the palate throughout ontogeny were analysed and characterised including molecular and morphological phylogenetic frameworks, and the shifts in morphospace occupation and disparity across ontogenetic stages were also analysed. The results show that, contrary to what might be expected from previous ontogenetic analyses in the dorsal view of the cranium, the shape and relative size of the suborbital fenestrae, and the shape of the palatines and their relative position to the suborbital fenestrae are more important than changes in the rostral length of the palate. Furthermore, crocodylian clades occupy distinct areas of the palatal morphospace from early ontogenetic stages onwards, and disparity analyses show an increase in disparity during ontogeny that is heterogeneously distributed between ontogenetic stage shifts. Finally, the analyses between ontogenetic trajectories show that some species have distinct trajectories, and that these differences are more pronounced in some brevirostrine and longirostrine taxa.

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Más información:

• Referencia: de Celis, A., Narváez, I., Ortega, F. 2023. A geometric morphometric approach to palatal ontogeny in Crocodylia. In: Malhotra, A., Harrison, X., Jehle, R., Ruthsatz, K., Ting, K.S., Garner, T., Herrel, A., Gower, D.J., Crnobrnja-Isailović, J., Corti, C., Naumov, B., Torres-Sánchez, M., Jablonski, D., Orton, F., Vamberger, M., Jelić, D., Ihlow, F., Gvoždík, V., O'Shea, M., Maddock, S., Kruger, N., Wilkinson, J., Pawlik, A., Morris, R., Martin, R., Deepak, V. (Eds.). Book of abstracts of the 22nd European Congress of Herpetology, University of Wolverhampton, UK, 4th-8th September 2023.