Gryposaurus monumentensis, un nuevo hadrosaurido de Utah (EE.UU.)

La revista Zoological Journal of Linnean Society acaba de publicar en su último número la descripción de un nuevo dinosaurio hadrosaurido del Cretácico Superior (Campaniense) de Utah (EE.UU.). Se trata de un cráneo prácticamente completo y bien conservado tal y como se ve en la fotografía. Gryposaurus se trata de un género de hadrosaurido representado por varias especies lo que le hace uno de los géneros más diversificado de hadrosauridos. Presenta una bateria dental típica de estos dinosaurios con más de trescientos dientes, y un nasal algo inflado.

La referencia original es: Gates, T. A. & Sampson, S. D. 2007. A new species of Gryposaurus (Dinosauria: Hadrosauridae) from the late Campanian Kaiparowits Formation, southern Utah, USA. Zoological Journal of the Linnean Society, 151, 2, 351-376.

El resumen original del trabajo es el siguiente:
A new species of the hadrosaurine hadrosaurid Gryposaurus was discovered in the late Campanian Kaiparowits Formation of southern Utah. Gryposaurus monumentensis, sp. nov. is distinguished from other Gryposaurus species by possessing a more robust skull, enlarged clover-shaped prongs on the predentary oral margin, an anteroposteriorly narrow infratemporal fenestra, and other autapomorphies plausibly associated with feeding adaptations. The derived morphology revealed in G. monumentensis necessitates revision of the generic diagnosis of Gryposaurus, including the addition of synapomorphies that further aid in distinguishing this taxon from Kritosaurus. A revised phylogenetic analysis places Gryposaurus within a monophyletic clade that includes Brachylophosaurus and Maiasaura. Gryposaurus monumentensis represents the most southern example of Gryposaurus, and underlines the remarkable diversification and long duration of this genus. Based on the phylogenetic, geographical, and stratigraphic evidence at hand, Gryposaurus was the most diverse genus within Hadrosaurinae; it also possessed one of the largest geographical and stratigraphic distributions, spanning more than five million years of the Campanian, and ranging from Alberta in the north to Utah (and possibly Texas) in the south.