8.9.15

Faunas de tetrápodos triásicos en el 63rd SVPCA



Entre los varios posters presentados por el Grupo de Biología Evolutiva de la UNED en la 63ª edición del Symposium of Vertebrate Palaeontology and Comparative Anatomy (SVPCA) que tuvo lugar la semana pasada en Southampton, uno de ellos estaba centrado en faunas de tetrápodos acuáticos del Triásico Superior. En el póster, firmado por Carlos de Miguel Chaves y colaboradores, se describen los restos de varios clados de tetrápodos acuáticos hallados hace casi 15 años en la localidad turolense de Manzanera, citados por primera vez en 2003. El material incluye elementos de notosauroideos, ictiosaurios, temnospóndilos y osteodermos de placodontos cyamodontoideos.

Aquí tenéis el abstract:

Several outcrops providing Upper Triassic vertebrate remains have been identified in the Keuper levels (Carnian) of the locality of Manzanera (Teruel Province, Spain). These fossils belong to different tetrapod clades. The detailed study of abundant material, including numerous unpublished specimens, allows us to modify and extend the previously proposed faunal list of this locality. The remains assigned to nothosauroids consist of several vertebrae and ribs. Their previous attribution to Nothosauria is refuted, based on the presence of infraprezygapophyses and infrapostzygapophyses in the neural arches. Within sauropterygians these characters are only present in the nothosauroid Simosaurus gaillardoti and the pistosauroid Bobosaurus forojuliensis. The morphology of the vertebrae and the presence of distally expanded ribs suggest that the remains from Manzanera could belong to Simosaurus, a taxon so far not recognized in the Iberian record. There are placodont elements that consist of several isolated osteoderms of the carapace of cyamodontoids. Two isolated osteoderms have the same features of those of the placochelyd Psephoderma. Another osteoderm similar to those that conform the dorsolateral ridge in Psephosauriscus mosis is also identified. Several partial vertebral centra from the caudal region of ichthiosaurs are also recognized. The disc-like shape of the centra is a derived condition that is not present in the basal forms of ichthyopterygians. These elements represent the first record of Ichthyosauria in the Iberian Keuper, constituting the second reference to this group in the Iberian Triassic. The faunal list from Manzanera also includes temnospondyls, represented by fragmentary cranial remains.

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