Sauropod haemal arches


Alejandro Otero, Pablo Ariel Gallina, Juan Ignacio Canale and Alejandro Haluza 

Abtract. Sauropod haemal arches are caudal bony structures that have been traditionally incorporated into two different types observed in different anatomical views: Y-shaped (anterior view) and forked (lateral view). This research proposes a classification combining information observed in anterior and lateral views. Four types of ‘Y-shaped’ and six types of ‘V-shaped’ chevrons were recognised. Complete chevron series in some eusauropods allows the comparison of topological equivalent structures along the tail and also among taxa. A basal titanosaur from Argentina exhibits mid-caudal chevron morphology in which more than one cranial and caudal process is present, arising from the distal blades as well as from the proximal rami, a condition not seen before in a sauropod dinosaur. The morphological variability seen in sauropod chevrons along the tail is in close relationship with the development and distribution of muscle. caudofemoralis longus, as seen in extant crocodiles and as previously proposed for non-avian theropods and for caudal centra and transverse processes of sauropod dinosaurs. Two new characters related to middle chevrons are proposed here, in which the transitional morphology is described.

Otero, A., Gallina, P. A., Canale,  J. I. and Haluza, A. 2011. Sauropod haemal arches: morphotypes, new classification and phylogenetic aspects.Historical Biology iFirst article, 2011, 1–14.


Aquí les dejo una fantástica reconstrucción en vida del nuevo integrante de la gran familia de dinosaurios de Rincón de los Sauces, Neuquén, Argentina: Narambuenatitan palomoi, realizada por el Dr. Ezequiel Vera, que además de ser un gran Paleobotánico y excelente dibujante, es un gran amigo. Poco a poco, el proyecto en marcha, nos permitirá ir contando la antigua historia que esconde esta región de Norpatagonia, no solo con el estudio de los ejemplares hallados, sino además, con las reconstrucciones de su aspecto anatómico que de alguna manera les devolverá la vida.

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