Literatura académica sobre el tema "Cetiosauridae"

En este trabajo se describen en detalle las vértebras y costillas cervicales del dinosaurio saurópodo Galvesaurus herreroi. El ejemplar proviene de la Formación Villar del Arzobispo (Titónico-Berriasiense medio?) de Galve (Sistema Ibérico, Teruel, Aragón, España). Se estudian cuatro vértebras cervicales y dos costillas cervicales recuperadas en el yacimiento de Cuesta Lonsal. Estas vértebras posiblemente pertenecen al mismo individuo que el holotipo. El taxón “Galveosaurus herreroi” descrito sobre el mismo ejemplar deviene en un sinónimo posterior. Las vértebras cervicales presentan unos centros vertebrales fuertemente opistocélicos, con pleurocelos bien desarrollados, profundos y divididos en el caso de las cervicales medias. El arco neural es relativamente alto. La laminación está bien desarrollada en el arco neural formada fundamentalmente por las láminas acdl, pcdl, cpol, cprl, sprl, prdl y podl. Además presenta dos láminas accesorias, conectadas con la lámina postzigodiapofisial. Tanto el centro vertebral como el arco neural se encuentra bien neumatizados. Las vértebras cervicales de Galvesaurus presentan una morfología que permite incluirlas en Neosauropoda. El estudio cladístico realizado a partir de la matriz de Wilson (2002) con algunas modificaciones, demuestra también que Galvesaurus se sitúa en el clado Neosauropoda, y posiblemente en la base de Macronaria, aunque la escasez de información de los taxones de esta parte de cladograma deja abiertas otras posibilidades. La propuesta de algunos autores de situar a Galvesaurus como un Cetiosauridae o lo que es lo mismo un Eusauropoda fuera de Neosauropoda no es coherente con nuestros resultados.

SynopsisA limb bone from the Bathonian of the Isle of Skye, previously identified as a possible femur of the sauropod dinosaur Cetiosaurus, is reassessed in light of comparisons with other sauropod material, including the lectotype of Cetiosaurus oxoniensis. Although the closest match for the Skye bone is found to be a left humerus identified as Cetiosaurus oxoniensis by J. Phillips in 1871, the identification of the Skye bone as cetiosaurid is unsafe, given the poor diagnostic power of long bones in most sauropod taxa.

The Galve fossil sites (province of Teruel, Spain) have provided many Mesozoic vertebrate remains. Among these are isolated sauropod dinosaur bones, including one taxon reported only from this locality, Aragosaurus ischiaticus. Here, a new species is named from the Tithonian deposits of the Villar del Arzobispo Formation, of Galve (Teruel province, Spain), Galveosaurus herreroi gen. et sp. nov. It is represented by two humeri, one sternal plate, one ischium, one scapula, one cervical vertebra, one caudal dorsal vertebra, five caudal vertebrae, one Y-shaped chevron and some fragments of ribs. This new species is an eusauropod dinosaur that shows primitive features such as a slightly curved ischium with an unexpanded distal end, amphicoelous vertebrae, neural spine not bifid and an unforked chevron. It appears to be closer to cetiosaurid genera such as Barapasaurus or Cetiosaurus. This new basal sauropod lived at the same time as the eusauropod Lourinhasaurus alenquerensis from Portugal. These are both relict genera that survived in the Iberian Peninsula when more derived neosauropods, such as Losillasaurus or Dinheirosaurus, had taken over other parts of Iberia.

Most recent studies of dinosaur phylogeny have concentrated on theropods and ornithischians. As a result, the evolutionary relationships of sauropod dinosaurs are poorly understood. In this paper previous studies of sauropod phylogeny are reviewed and contrasted with the results of a recent cladistic analysis. This analysis forms the basis for a reconstruction of sauropod phylogeny. Sauropods diverged from other dinosaurs at some time in the Upper Triassic, but a large part of their early history is totally unknown. Vulcanodon is currently the most primitive sauropod. Many, but perhaps not all, of the Jurassic Chinese sauropods form a monophyletic radiation (the Euhelopodidae) which may reflect the geographic isolation of China during the Lower Jurassic. Members of the Euhelopodidae, such as Mamenchisaurus , are not considered to be closely related to the Diplodocidae. ‘Forked’ chevrons, which have played such an important role in previous studies of sauropod phylogeny, are here considered to have evolved twice within the Sauropoda. This convergence may reflect a correlation between chevron shape and the use of the tail as a weapon within these two sauropod families. The ‘Neosauropoda’ (sister group to the Euhelopodidae) contains the Brachiosauridae, Camarasauridae and the new superfamilies Titanosauroidea and Diplodocoidea. The Cetiosauridae (here defined in a rather restricted sense) is also provisionally included within the Neosauropoda, but may be removed in future studies. The enigmatic Upper Cretaceous sauropod, Opisthocoelicaudia , is thought to be the sister taxon to the Titanosauridae and not a camarasaurid as previously suggested. The Diplodocoidea contains two well established families, the Dicraeosauridae and Diplodocidae, and the new family Nemegtosauridae. Finally, an overview of sauropod phylogeny is compared with recently published palaeogeographic reconstructions. There are many difficulties associated with the analysis of sauropod biogeographic distribution. Nevertheless, some aspects of sauropod phylogeny may be linked to the break-up of Laurasia and Gondwanaland during the Jurassic and Cretaceous.