Mostrando entradas con la etiqueta Anfibios. Mostrar todas las entradas
Mostrando entradas con la etiqueta Anfibios. Mostrar todas las entradas
8.9.15 , , , 0 comentarios

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 The detailed study of abundant material, including numerous unpublished specimens, allows us to modify and extend the previously proposed faunal list of this locality.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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Más información:
1.2.13 , , , 0 comentarios

Aquí nos gustan los anfibios (fósiles o no)


Aquí nos gustan los anfibios y como se dice en el título sean fósiles o no. Desde este blog damos la bienvenida a Ichthyosaura randeckensis un nuevo urodelo fósil del Mioceno temprano europeo que mantiene unos estrechos lazos de sangre con uno de nuestros tritones más amenzados y "Vulnerable", Ichthyosaura (Mesotriton) alpestris o popularmente denominado tritón alpino.

El artículo donde se describe este nuevo anfibio aparace publicado en la revista científica Journal of Vertebrate Paleontology y a modo de nota os dejamos el abstract:

A new species of salamandrid is named and described from the Miocene of Randeck Maar, a long-term volcanic lake deposit in southern Germany. Based on a fully articulated specimen, Ichthyosaura randeckensis is named and described as a 3–4 cm long newt with a robust posterolateral process of the frontal, a heavily ornamented skull roof, and a premaxilla with spike-like, parallel alary processes framing a slender fontanelle posteriorly. In a phylogenetic analysis of 14 salamandrid taxa and 38 morphological characters, I. randeckensis is found to nest with I. alpestris, with which it shares apomorphic character states in the morphology of premaxilla and nasal. The present analysis employed more morphological characters than hitherto considered, highlighting the need to conduct more osteological studies of extant salamanders. Its results are largely consistent with recent molecular phylogenetic studies: Tylototriton and Pleurodeles form a clade, with Notophthalmus and Euproctus falling within unresolved trichotomies, followed by Cynops and Ommatotriton as successive crownward clades, then Triturus sensu stricto (T. marmoratus and T. cristatus), and finally Lissotriton and Ichthyosaura as terminal sister taxa.

Más información:
  • Rainer R. Schoch & Michael W. Rasser (2013) A new salamandrid from the Miocene Randeck Maar, Germany. A new salamandrid from the Miocene Randeck Maar, Germany, 33(1): 58–66. doi: 10.1080/02724634.2012.716113.
  • Imágenes tomada de la publicación: imagen izquierda ejemplar tipo de la especie; imagen derecha dibujo del esqueleto de Ichthyosaura randeckensis.
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