Montanazhdarcho

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Montanazhdarcho
Temporal range: Late Cretaceous, 74 Ma
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Pterosauria
Suborder: Pterodactyloidea
Clade: Azhdarchoidea
Genus: Montanazhdarcho
Padian, de Ricqlès & Horner, 1995
Type species
Montanazhdarcho minor
Padian, Ricqlès & Horner, 1995

Montanazhdarcho is a genus of azhdarchoid pterosaur from the late Cretaceous Period (Campanian stage) of North America, known from only one species, M. minor.

The genus was named in 1993 by Kevin Padian, Armand de Ricqlès, and Jack Horner,[1] again published by the same authors in 1995[2] and fully described in 2002.[3]

Map showing global distribution of faunas containing small-medium and giant-sized azhdarchids

The type species is Montanazhdarcho minor. The genus name refers to Montana and to the related species Azhdarcho. The specific name means "the smaller one" in Latin, a reference to the relatively small size in comparison to closely related forms.

The holotype, MOR 691 (Museum of the Rockies), was found by Robert W. Harmon in Glacier County, in the territory of the Blackfoot, in sandstone of the Upper Two Medicine Formation, a layer about 74 million years old. The fossil is largely uncompressed and that of an adult exemplar, as established by a study of the bone by de Ricqlès. It consists of a partial left wing, lacking the outer three wing finger phalanges, a complete shoulder girdle, a crushed cervical vertebra and two fragments of the symphysis of the mandible. The jaws were edentulous, i.e.: they lacked teeth.

Montanazhdarcho was by the authors assigned to the Azhdarchidae, mainly based on the elongated form of the neck vertebra. Compared to other azhdarchids, it was small; the fragments of humerus, radius, and carpal suggest an animal with a 2.5 metre wingspan (eight feet). Its ulna was longer than the wing metacarpal, which is atypical for azhdarchids. However, recent studies suggest that it was a non-azhdarchid azhdarchoid, probably a tapejarid.[4]

See also[edit]

References[edit]

  1. ^ Padian, K., Horner, J.R., and de Ricqlès, A.J. (1993). "A new azhdarchid pterosaur from the Two Medicine Formation (Late Cretaceous, Campanian) of Montana, identified on the basis of bone histology." Journal of Vertebrate Paleontology, 13: 52A
  2. ^ K. Padian, A. J. de Ricqlès, and J. R. Horner (1995), "Bone histology determines identification of a new fossil taxon of pterosaur (Reptilia: Archosauria)", Comptes Rendus de l’Academie des Science, Serie II (320): 77-84
  3. ^ McGowen, M.R.; Padian, K.; de Sosa, M.A.; Harmon, R.J. (2002). "Description of Montanazhdarcho minor, an azhdarchid pterosaur from the Two Medicine Formation (Campanian) of Montana". PaleoBios. 22 (1): 1–9. 
  4. ^ Carroll, N. REASSIGNMENT OF MONTANAZHDARCHO MINOR AS A NON-AZHDARCHID MEMBER OF THE AZHDARCHOIDEA, SVP 2015