Redescripción de Nemegtosaurus (Abtracto)

Wilson, J.A. (2005). Redescription of the Mongolian sauropod "Nemegtosaurus mongoliensis" Nowinski (Dinosauria: Saurischia) and comments on Late Cretaceous sauropod diversity. Journal of Systematic Palaeontology 3: 283-318.

Abstract: "The isolated skulls of "Nemegtosaurus mongoliensis" and "Quaesitosaurus orientalis" from the Nemegt Basin of Mongolia are among the most complete sauropod cranial remains known from the Late Cretaceous, yet their evolutionary relationships to other neosauropods have remained uncertain. Redescription of the skull of "Nemegtosaurus" identifies key features that link it and its closely related counterpart "Quaesitosaurus" to titanosaur sauropods. These include a posterolaterally orientated quadrate fossa, `rocker'-like palatobasal contact, pterygoid with reduced quadrate flange and a novel basisphenoid–quadrate contact. Other features are exclusive to "Nemegtosaurus" and "Quaesitosaurus", such as the presence of a symphyseal eminence on the external aspect of the premaxillae, a highly vascularised tooth bearing portion of the maxilla, an enclosed `maxillary canal', orbital ornamentation on the postorbital, prefrontal and frontal, exclusion of the squamosal from the supratemporal fenestra and dentary teeth smaller in diameter than premaxillary and maxillary teeth.

"Re-examination of Late Cretaceous sauropod distributions in the light of this well-supported phylogenetic hypothesis has important implications for their diversity at the end of the Mesozoic in Asia and elsewhere. Cretaceous Asian sauropod faunas consist solely of titanosauriforms, which probably migrated there from other landmasses during the Late Jurassic, during which time neosauropods were absent from Asia. Globally, narrow-crowned titanosaurs and rebbachisaurids radiated during the Cretaceous, but only titanosaurs survived into the latest Cretaceous. These late-surviving sauropods flourished on most continental landmasses until the end of the Maastrichtian."