7.6.19

¿En qué piensan los eusuquios? en formato tesis


El pasado jueves 6 de junio, en la Facultad de Humanidades de la UNED, Alejandro Serrano defendió su memoria de tesis titulada "Análisis de la evolución neurocraneal en la radiación temprana de Eusuchia". El resultado, por supuesto, fue la obtención del título de Doctor en Ciencias, obteniendo además la máxima calificación, Sobresaliente cum laude.

La tesis ha sido dirigida por Francisco Ortega, de la Universidad Nacional de Educación a Distancia (UNED), y por Fabien Knoll, (ARAID - Conjunto Paleontológico de Teruel- Dinópolis) y supone el reconocimiento al duro esfuerzo y trabajo llevado a cabo en estados 5 años por parte de Alejandro en su labor de dar un poco de vida a los eusuquios de Lo Hueco. Aquí tenéis el abstract de la tesis:

Crocodylomorpha is a very successful lineage, spanning 230 million years from its origin, in the Late Triassic, to present day. Crocodylomorph remains are common in Mesozoic and Cenozoic fossil sites across the world, showing a high diversity and abundance in these remote ancient ecosystems. The fossil site of Lo Hueco (Upper Cretaceous, Cuenca, Spain) is noteworthy because of the high number and exceptional preservation of the crocodylomorph remains found. The morphological characters in Lo Hueco specimens allow establishing three basal eusuchian morphotypes, two of them diagnosed as new endemical species: Lohuecosuchus megadontos, Agaresuchus fontisensis and an indeterminate Allodaposuchidae. The main aim of this PhD dissertation is to reconstruct and describe the inner skull cavities of several of the basal eusuchian specimens from the Lo Hueco fossil site. The specimens were scanned using CT-Technology, which allows to observe the interior of the specimen and to reconstruct its inner cavities, including the brain itself, inner ear and pharyngotympanic and paranasal sinus systems. The inner cavities also housed some of the neurosensorial organs of these animals. These regions have been linearly and volumetrically measured to estimate the neurosensorial and cognitive capabilities of these animals. These data were compared to those of several extant crocodylians of different sizes, and to those of some specimens from the outgroup of Crocodylomorpha, such as birds, squamates and turtles. The results show that inner skull cavities of crocodylomorphs are very conservative structures, being those of the extant specimens very similar to the inner skull cavities of the basal members of the group. However, some characters changes during the course of evolution following a phylogenetyc pattern, such as the shape of the caudodorsal region of the cerebrum, the shape of the intertympanic diverticula or the relative length of the median pharyngeal sinus. Our results also suggest that the neurosensory and cognitive capabilities of extant crocodylians, such as a sharp olfactory and visual acuity, or an adaptation to low-frequence hearing, were already present in early members of Eusuchia.

Como es tradición en estos eventos de enorme felicidad, al final del acto oficial de lectura y defensa de la tesis no pudo faltar la ya típica celebración. Sólo una cosa más: ¡enhorabuena Alejandro!


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Más información:
  • Referencia: Serrano Martínez, A. 2019. Análisis de la evolución neurocraneal en la radiación temprana de Eusuchia. Tesis Doctoral. UNED, Madrid.
  • Imágenes: Arriba, Alejandro Serrano al comienzo de la defensa de su tesis; abajo, el ya doctor junto a un nutrido grupo de paleontólogos y restauradores del Grupo de Biología Evolutiva de la UNED y algunas invitadas más.

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