Macrogryphosaurus

Macrogryphosaurus (meaning "big enigmatic lizard") is a genus of elasmarian dinosaur from the Coniacian age Upper Cretaceous Sierra Barrosa Formation (Neuquén Group) of Argentina in Patagonia. It was described by Jorge Calvo and colleagues in 2007, with M. gondwanicus as the type and only species.

==Discovery and naming== thumb|left|Satellite image of the terrain of the Neuquén Group, the geologic unit Macrogryphosaurus is from In May 1999, during field work at Mari Menuco Lake, Argentina (sixty kilometres northwest of Neuquén) conducted by the National University of Comahue, an articulated, nearly complete dinosaur skeleton was discovered and excavated. It was brought to the attention of the palaeontologists by young boy Rafael Moyano, who had discovered it. Originally reported to hail from the Portezuelo Formation of the Neuquén Group, its locality was later revised to be in the Sierra Barrosa Formation of the same geologic group. This unit is dated to the Coniacian age of the Late Cretaceous. Noted for bony plates on its thorax, it was identified as a large species of ornithopod.