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[dinosaur] Juvenile allosauroid from Upper Jurassic of Portugal




Ben Creisler
bcreisler@gmail.com

A new paper:

Elisabete Malafaia, Pedro Mocho, Fernando Escaso & Francisco Ortega (2016)
A juvenile allosauroid theropod (Dinosauria, Saurischia) from the Upper Jurassic of Portugal.
Historical Biology (advance online publication)
doi:  http://dx.doi.org/10.1080/08912963.2016.1231183  
http://www.tandfonline.com/doi/abs/10.1080/08912963.2016.1231183?journalCode=ghbi20



A new specimen of a theropod dinosaur found in Upper Jurassic sedimentary levels of the Lusitanian Basin (Portugal) is described. The specimen includes axial (cervical, dorsal, and caudal vertebrae and ribs) and pelvic elements, corresponding to a small-sized and juvenile individual. This specimen is one of the most complete theropod dinosaur from the Upper Jurassic of Portugal, and the only evidence of a post-hatchling juvenile theropod individual currently recognized in this record. The phylogenetic analysis recovered the new specimen as a basal Allosauroidea. It presents a combination of characters shared with other allosauroids already known in the Upper Jurassic of the Lusitanian Basin, Allosaurus and Lourinhanosaurus, but also some differences relative to both taxa. Some of these differences may be related to the juvenile condition of the specimen, but other unusual features cannot be properly explained by ontogeny, and are interpreted as having taxonomic significance. This combination of features might justify the description of a new theropod taxon for the Portuguese Upper Jurassic. Nevertheless, the presence of three sympatric and almost synchronic, closely related basal allosauroids requires further exploration of their intra- or interspecific variability.