PSEUDASTURIDAE MAYR, 1998

Mayr, Gerald, 2002, On the osteology and phylogenetic affinities of the Pseudasturidae - Lower Eocene stem-group representatives of parrots (Aves, Psittaciformes), Zoological Journal of the Linnean Society 136 (4), pp. 715-729 : 717

PSEUDASTURIDAE MAYR, 1998

MONOPHYLY

The Pseudasturidae exhibit a highly characteristic osteology and are clearly distinguished from all other avian taxa. All pseudasturid taxa known so far further exhibit a very similar morphology. However, owing to the different kind of preservation of the respective specimens (articulated skeletons in Messel and the Green River Formation vs. isolated bones in the London Clay deposits), not all of the following presumably autapomorphic features are visible in all taxa of the Pseudasturidae : (1) skull with large, caudally projecting processus supraorbitales (visible in the Messel specimens of Pseudastur macrocephalus ); (2) sternum with strongly protruding apex carinae (visible in the holotypes of ‘ Primobucco ’ olsoni and Serudaptus pohli ); (3) proximal end of humerus without foramen pneumaticum at bottom of fossa pneumotricipitalis (visible in the holotype of Pulchrapollia gracilis ); (4) distal end of ulna with marked depressio radialis; (5) fossa poplitea at distal end of femur marked and bordered by sharp and pronounced crista supracondylaris medialis (visible in the holotype of Pulchrapollia gracilis ); (6) medial foramen vasculare proximale much larger than lateral for. vasc. prox. (visible in the holotype of Pulchrapollia gracilis and the conspecific specimen figured by Mayr & Daniels, 1998: fig. 17i); (7) second toe very thin and trochlea metatarsi II of tarsometatarsus very small. Other putatively derived characters which were listed by Mayr (1998a) in the diagnosis of the Pseudasturidae are also shared with the Psittacidae .