Reconstrucción tridimensional de una tortuga marina mesozoica en las VIII Jornadas de Salas de los Infantes

Una de las técnicas que actualmente están permitiendo la obtención de abundante información en paleontología, hasta ahora no accesible, es aquella basada en el escaneado de los fósiles y su reconstrucción virtual tridimensional. De esta manera, muchas superficies de los especímenes fósiles no observables a simple vista, por estar cubiertas por sedimento o estar la disposición de diversos elementos anatómicos superpuestos unos a otros, pueden ser detalladamente reconstruidas. Este es el caso de un ejemplar de tortuga del Cretácico Superior de Eslovenia, sometido a un detallado proceso de reconstrucción que ha sido explicado con detalle en las VIII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno.

El resumen de esta contribución es el siguiente:

X-Rays Computerized Tomography (CT), and the techniques later developed to acquire a greater resolution as X-Rays Computerized Microtomography (MicroCT), represents a tool of great utility as complement to the traditional anatomical studies, as it allows the visualization and quantification of internal structures. Thus, although these techniques have been mainly used in fields related to medicine and industry, in recent years they have been applied in other disciplines, including paleontology, offering novel results as they allow the analysis of structures and surfaces hidden by sediment or corresponding to the internal structure of fossil remains.

Here is an example of the application of these techniques as a complement to the traditional systematic studies, generally applied to the field of vertebrate paleontology. The processed specimen corresponds to a partial skeleton of a sea turtle, coming from the Upper Cretaceous (Santonian-Campanian) of Dobravlje, in Slovenia. The bone remains of the specimen are partially included in a limestone matrix. In order to carry out its three-dimensional reconstruction and facilitate its subsequent study, it was scanned with the Nikon XTH225 ST Micro CT scanner located at the University of Bristol, obtaining 3,141 projections and a final pixel size of 0.066 mm. The tomograms obtained were processed using the AVIZO LITE 9 software for the individual segmentation of each of the bones and their three-dimensional extraction from the matrix without damaging the specimen. To soften the imperfections generated during the segmentation process with Avizo Lite 9 (such as cracks, roughness or irregularities), Geomagic Studio 2012 was used. Subsequently, the models obtained were reloaded into the Avizo Lite 9 program to compose them again with the set of segmented bones. Finally, the final images were obtained through captures from all angles and combinations of interest for the present study. These images were sorted and prepared with the Photoshop C6 raster graphics editor.

The application of these techniques in the study of fossil turtles is very novel nowadays. The model obtained will facilitate the subsequent precise systematic study of this specimen.

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Más información:

• Referencia: Ciudad-Real, M., Pérez-García, A., Jurkovšek, B., Jurkovšek, T., Martínez, C. 2019. Application of computerized tomography for the reconstruction of the partial skeleton of a turtle of the Upper Cretaceous of Slovenia. Póster. Libro de resúmenes del VIII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno: 51.
• Imagen: Ejemplar de tortuga de Eslovenia y detalle de su reconstrucción preliminar.