Monday, July 30, 2012

[Paleontology • 1995] Montanazhdarcho minor • an azhdarchid pterosaur from the Two Medicine Formation (Late Cretaceous, Campanian) of Montana.



The wing skeleton of the Campanian azhdarchid pterosaur Montanazhdarcho minor Vidian et al. 1995 is described and compared to other Cretaceous pterosaurs. It is distinguished from all other known azhdarchids by its small mature size, among other characters. Notable features include elongated cervical vertebrae with weak neural crests, a ring-like pectoral girdle, and an unwarped deltopectoral crest that is 30% of the length of the humerus. The ulna is slightly longer than the wing metacarpal, and the articular surface of the radius lacks a central pneumatic foramen. The wing metacarpal has a rounded dorsal condyle but there is no median ridge between the distal condyles. The mandible is edentulous, further support is given to the reduced distal expansion of the deltopectoral crest as an azhdarchid svnapomorphv. 





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
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.
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.

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