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Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae, Ornithurae). Bulletin of the AMNH ; no. 286

Show simple item record Clarke, Julia A. en_US Peabody Museum of Natural History. en_US 2005-10-06T14:15:20Z 2005-10-06T14:15:20Z 2004 en_US
dc.description 179 p. : ill. ; 26 cm. en_US
dc.description Includes bibliographical references (p. 157-167). en_US
dc.description.abstract Charles Darwin commented that Ichthyornis, as one of the "toothed birds" from the late Cretaceous of Kansas, offered some of "the best support to the theory of evolution" (in litt., C. Darwin to O.C. Marsh, August 31, 1880). Ichthyornis figures no less prominently today. It is one of the closest outgroups to crown clade Aves, and remains one of the only Mesozoic avialans known from more than a handful of specimens. As such, Ichthyornis is an essential taxon for analyses of deep divergences within Aves because of its influence in determining the morphologies ancestral to the crown clade. Ichthyornis, however, has languished in need of new anatomical description and taxonomic revision. Many of the best Ichthyornis specimens were largely inaccessible, plastered into Yale Peabody Museum (YPM) exhibit mounts for nearly a century. The focus of this study was the entire YPM Ichthyornis collection, the largest at any institution. The elements removed from the mounts were identified to the specimens with which they were originally associated. Detailed morphological study of the 81 YPM specimens yielded the following results: (1) there is evidence for only one species of Ichthyornis, rather than the eight previously proposed; (2) 78 specimens are part of this species, Ichthyornis dispar; (3) two previously identified species are not part of Ichthyornis; and (4) one new species is identified. This analysis also provided a case study in the application of phylogenetic nomenclature at the species level. The morphology of Ichthyornis dispar is described in detail from the holotype and referred specimens. Phylogenetic analyses of 202 morphological characters, scored for 24 terminal taxa, evaluated the relationships among Mesozoic ornithurines including Ichthyornis dispar and the newly identified taxa. Analysis of 23 core taxa produced two most parsimonious trees (L: 384, CI: 0.66). Marsh's "Ichthyornithiformes" is not monophyletic: Two previously named species of Ichthyornis as well as Apatornis celer are placed as more closely related to or as part of Aves. The results of the phylogenetic analyses have implications for previous hypotheses of the timing and pattern of the origin of Aves. en_US
dc.format.extent 6741787 bytes
dc.format.mimetype application/pdf
dc.language eng en_US
dc.language.iso en_US
dc.publisher New York, NY : American Museum of Natural History en_US
dc.relation.ispartofseries Bulletin of the American Museum of Natural History ; no. 286 en_US
dc.subject.lcc QH1 .A4 no.286 2004 en_US
dc.subject.lcsh Ichthyornis dispar. en_US
dc.subject.lcsh Ichthyornis. en_US
dc.subject.lcsh Apatornis. en_US
dc.subject.lcsh Birds, Fossil. en_US
dc.subject.lcsh Birds -- Phylogeny. en_US
dc.subject.lcsh Birds -- Origin. en_US
dc.subject.lcsh Birds -- Evolution. en_US
dc.subject.lcsh Paleontology -- Cretaceous. en_US
dc.subject.lcsh Paleontology -- Mesozoic. en_US
dc.title Morphology, phylogenetic taxonomy, and systematics of Ichthyornis and Apatornis (Avialae, Ornithurae). Bulletin of the AMNH ; no. 286 en_US
dc.title.alternative Ichthyornis and Apatornis en_US
dc.type text en_US

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  • Bulletin of the American Museum of Natural History
    The Bulletin, published continuously since 1881, consists of longer monographic volumes in the field of natural sciences relating to zoology, paleontology, and geology. Current numbers are published at irregular intervals. The Bulletin was originally a place to publish short papers, while longer works appeared in the Memoirs. However, in the 1920s, the Memoirs ceased and the Bulletin series began publishing longer papers. A new series, the Novitates , published short papers describing new forms.

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