Muzquizopteryx

Muzquizopteryx is a genus of pterodactyloid pterosaur (flying reptile) from the Late Cretaceous of what is now Coahuila, Mexico.

In the nineties José Martínez Vásquez, a worker at the chalk quarry of El Rosario, uncovered a skeleton of a pterosaur. This he handed to a quarry official, who had it bricked in on the face of an office wall as a decorative piece. After its unique scientific value had been recognised in 2002, the specimen was acquired by the Universidad Nacional Autónoma de México. Subsequently it was studied by a combined team of the University of Karlsruhe and the University of Heidelberg, in this financially supported by the Volkswagen company. The specimen was scientifically reported in 2004.[1]

In 2006 the type species Muzquizopteryx coahuilensis was named and described by Eberhard Frey, Marie-Céline Buchy, Wolfgang Stinnesbeck, Arturo González-González and Alfredo di Stefano. The generic name is derived from the Múzquiz district and a Greek πτέρυξ, pteryx, "wing". The specific name is derived from the state of Coahuila.[2]

Muzquizopteryx is based on holotype UNAM IGM 8621, found in the El Rosario layers, early Coniacian-aged rocks.[3] It consists of a nearly complete, articulated skeleton that includes soft tissue remains, among them long fossilised tendons along both sides of both lower arms. The specimen represents an adult individual.[2]

In 2012 a second specimen was reported, MUDE CPC-494, again uncovered by a quarry worker, perhaps at the same site, and sold to a private collector. It was later acquired by the Museo del Desierto Saltillo. It consists of the right upper wing of a subadult individual, with about 81% of the length of the holotype. As its provenance probably consists of slightly older layers from the late Turonian and the remains are limited, it was referred to a Muzquizopteryx sp.[4]

Muzquizopteryx was relatively small for a pterodactyloid pterosaur, with a wingspan of around two metres (6.6 ft). It had an elongated head with a convex upper profile, ending at the back of the head in a backward pointing short rounded crest. The jaws were toothless. The arms were very robust with the humerus featuring a large hatchet-shaped deltopectoral crest, indicating a strong wing musculature. The pteroid bone was long and pointed towards the neck, supporting a flight membrane.[2]

Muzquizopteryx was by its describers assigned to the Nyctosauridae. It would then be the oldest known member of the group and the smallest known; indeed the smallest adult Late Cretaceous pterosaur discovered until 2006.[2] As Nyctosaurus is sometimes included with the Pteranodontidae, Muzquizopteryx too might be considered a member of that group under some classifications.