May 6, 2016

En la tarde del 15 de Abril se presentó en el I IMERP-XIV EJIP una breve comunicación sobre dientes de dinosaurios saurópodos del Jurásico Superior Portugués. En la presentación, a cargo de Pedro Mocho (UNED/SHN), se tratan los diferentes morfotipos de dientes de saurópodos presentes en la Cuenca Lusitánica durante el Jurásico Superior (Kimmeridgiense-Titoniense). Esta variabilidad se discute teniendo en cuenta la diversidad de este grupo en este territorio durante ese periodo, y se compara con la diversidad presente en las formaciones Morrison, Tendaguru y Villar del Arzobispo.

Os dejamos con el abstract del trabajo:

Several new tooth occurrences have been reported along the Lusitanian Basin, more precisely, in the localities of Guimarota, Pombal, Torres Vedras, Lourinhã, Caldas da Rainha and Peniche. The systematic study of this sample (more than 50 teeth) is relevant for the knowledge of the diversity of sauropods in this area during the Late Jurassic (early Kimmeridgian to late Tithonian). The four different tooth morphologies identified in the Portuguese Upper Jurassic record will be briefly described and discussed. One of the most common types can be distinguished by the presence of heart-shaped crowns with three different morphotypes described along the Lusitanian Basin. In general, they have pointed and asymmetrical apices and convex labial surfaces with a bulge extending apicobasally. These teeth are tentatively related to Turiasauria, a group of basal eusauropods present in the Upper Jurassic-lower Cretaceous of the Iberian Peninsula, which includes Turiasaurus, Losillasaurus and Zby. Several compressed cone-chisel-shaped teeth were identified in the Upper Jurassic of the Lusitanian Basin. These teeth present an important morphological variability possessing SI (crown height/maximum crown breadth) values higher than the spatulate-shaped teeth but lower than the pencil-shaped ones, a constricted base resulting in a peduncle that supports the expanded apices, and apicobasal bulges on the labial face. This mosaic of features was considered a synapomorphic morphology for titanosauriforms. Some apices bear a slight torsion relatively to the tooth axis (twisted axially through an arc of 30-45°) that was considered a synapomorphy of Brachiosauridae. Other two teeth morphologies are described for the Portuguese Late Jurassic. Spatulate-shaped teeth are characterized by straight and subparallel distal and mesial edges at the base of the crown, and by the presence of convex labial and concave lingual faces. The presence of a complex cingulum suggests the placement of these teeth within Macronaria. Finally, some teeth have a pencil-shaped morphology. This morphology is represented by sub-cylindrical crowns, an oval wear facet on the labial side, and high SI values. Herein, they are tentatively referred to Diplodocoidea. These four distinct types of teeth indicate the presence in the Lusitanian Basin of basal eusauropods, possible members of Turiasauria (heart-shaped teeth), diplodocoids (pencil-shaped teeth), basal macronarians (spatulate-shaped teeth) and titanosauriforms (compressed chisel-shaped teeth) during the early Kimmeridgian to late Tithonian. This agrees with the known paleodiversity previously known for the Portuguese Late Jurassic sauropods.

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Más información:
Referencia: Mocho P, Royo-Torres R, Ortega, F. 2016. Late Jurassic sauropod teeth from the Lusitanian Basin. New perspectives on the Evolution of Phanerozoic Biotas and Ecosystems (XIV EJIP Abstract book), 68.