| Muzquizopteryx Temporal range:
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|---|---|
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| Fossil skeleton | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Order: | †Pterosauria |
| Suborder: | †Pterodactyloidea |
| Clade: | †Aponyctosauria |
| Family: | †Nyctosauridae |
| Genus: | †Muzquizopteryx Frey et al., 2006 |
| Type species | |
| †Muzquizopteryx coahuilensis Frey et al., 2006
| |
Muzquizopteryx is a genus of nyctosaurid pterodactyloid pterosaur from the Late Cretaceous period (early Coniacian stage) of what is now Coahuila, Mexico.
In the 1990s, 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 recognized 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 Desert Museum and 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 2 meters (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.
Below is a cladogram showing the results of a phylogenetic analysis first presented by Andres and colleagues in 2014, and updated with additional data by Longrich and colleagues in 2018. They found Muzquizopteryx within the family Nyctosauridae.[5][6]
