A Lower Eocene Frigatebird from the Green River Formation of Wyoming (Pelecaniformes, Fregatidae) PDF Download
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Author: Storrs L. Olson Publisher: ISBN: Category : Birds, Fossil Languages : en Pages : 44
Book Description
A new subfamily, Limnofregatinae, is erected for the first known Tertiary specimens of the pelecaniform family Fregatidae. These are described as a new genus and species, Limnofregata azygosternon. The holotype is a nearly complete skeleton with feather impressions. Two additional specimens, consisting of a partial skeleton and a fragment of ulna, are referred to the same species. All are from freshwater lake deposits in the Lower Eocene Green River Formation of Wyoming, which are roughly 50 million years old. The principal differences between Limnofregata and modern frigatebirds (Fregata) are seen in its shorter and less hooked rostrum, proportionately shorter wings and longer hindlimb, in the lack of fusion in the pectoral girdle, and in the lack of extensive pneumatization of the skeleton. The fossilform is, nevertheless, well advanced along the lines of modern frigatebirds and nothing in its morphology seems to preclude its being ancestral to Fregata. The fossil provides additional support for placing the suborder Fregatae between the more primitive tropicbirds (suborder Phaethontes) and the members of the suborder Pelecani. Frigatebirds in the early Tertiary evidently occupied different habitats or a wider range of habitats than the modern forms and have only subsequently been restricted to a purely oceanic environment.
Author: Storrs L. Olson Publisher: ISBN: Category : Birds, Fossil Languages : en Pages : 44
Book Description
A new subfamily, Limnofregatinae, is erected for the first known Tertiary specimens of the pelecaniform family Fregatidae. These are described as a new genus and species, Limnofregata azygosternon. The holotype is a nearly complete skeleton with feather impressions. Two additional specimens, consisting of a partial skeleton and a fragment of ulna, are referred to the same species. All are from freshwater lake deposits in the Lower Eocene Green River Formation of Wyoming, which are roughly 50 million years old. The principal differences between Limnofregata and modern frigatebirds (Fregata) are seen in its shorter and less hooked rostrum, proportionately shorter wings and longer hindlimb, in the lack of fusion in the pectoral girdle, and in the lack of extensive pneumatization of the skeleton. The fossilform is, nevertheless, well advanced along the lines of modern frigatebirds and nothing in its morphology seems to preclude its being ancestral to Fregata. The fossil provides additional support for placing the suborder Fregatae between the more primitive tropicbirds (suborder Phaethontes) and the members of the suborder Pelecani. Frigatebirds in the early Tertiary evidently occupied different habitats or a wider range of habitats than the modern forms and have only subsequently been restricted to a purely oceanic environment.
Author: Storrs L. Olson Publisher: ISBN: Category : Birds, Fossil Languages : en Pages : 50
Book Description
A new subfamily, Limnofregatinae, is erected for the first known Tertiary specimens of the pelecaniform family Fregatidae. These are described as a new genus and species, Limnofregata azygosternon. The holotype is a nearly complete skeleton with feather impressions. Two additional specimens, consisting of a partial skeleton and a fragment of ulna, are referred to the same species. All are from freshwater lake deposits in the Lower Eocene Green River Formation of Wyoming, which are roughly 50 million years old. The principal differences between Limnofregata and modern frigatebirds (Fregata) are seen in its shorter and less hooked rostrum, proportionately shorter wings and longer hindlimb, in the lack of fusion in the pectoral girdle, and in the lack of extensive pneumatization of the skeleton. The fossilform is, nevertheless, well advanced along the lines of modern frigatebirds and nothing in its morphology seems to preclude its being ancestral to Fregata. The fossil provides additional support for placing the suborder Fregatae between the more primitive tropicbirds (suborder Phaethontes) and the members of the suborder Pelecani. Frigatebirds in the early Tertiary evidently occupied different habitats or a wider range of habitats than the modern forms and have only subsequently been restricted to a purely oceanic environment.
Author: Gerald Mayr Publisher: John Wiley & Sons ISBN: 111902076X Category : Science Languages : en Pages : 341
Book Description
Knowledge of the evolutionary history of birds has much improved in recent decades. Fossils from critical time periods are being described at unprecedented rates and modern phylogenetic analyses have provided a framework for the interrelationships of the extant groups. This book gives an overview of the avian fossil record and its paleobiological significance, and it is the only up-to-date textbook that covers both Mesozoic and more modern-type Cenozoic birds in some detail. The reader is introduced to key features of basal avians and the morphological transformations that have occurred in the evolution towards modern birds. An account of the Cenozoic fossil record sheds light on the biogeographic history of the extant avian groups and discusses fossils in the context of current phylogenetic hypotheses. This review of the evolutionary history of birds not only addresses students and established researchers, but it may also be a useful source of information for anyone else with an interest in the evolution of birds and a moderate background in biology and geology.
Author: Gerald Mayr Publisher: Springer Nature ISBN: 3030876454 Category : Science Languages : en Pages : 247
Book Description
This second, completely revised edition of “Paleogene fossil birds” gives a comprehensive, updated overview of the avian fossil record from a geological period that lasted from the end-Cretaceous mass extinction event (66 million years ago) to the end of the Oligocene epoch (23 mya). Paleogene avifaunas are highly diversified and not only feature unusual archaic groups without close living relatives but also offer unique insights into the evolution and biogeographic history of extant birds. The main body of the book constitutes an in-depth survey of the known diversity of Paleogene avifaunas. The reader is introduced into basic skeletal features of extinct avian taxa, with these fossil forms being placed into a phylogenetic context in the light of current hypotheses on the interrelationships of extant birds. The geographical and temporal occurrences of the various fossil groups are outlined and their evolutionary significance is discussed. Concluding sections inform more general aspects of Paleogene avifaunas, such as possible causes of major faunal changes. In addition to being a reference work for the early evolution of modern birds from a paleornithological perspective, the present work also enables researchers in other fields of vertebrate paleontology to gain an improved understanding of Paleogene ecosystems. Numerous color photos of representative specimens furthermore make the new edition attractive to a wider audience interested in the avian fossil record.
Author: Donald Farner Publisher: Elsevier ISBN: 0323157998 Category : Nature Languages : en Pages : 281
Book Description
Avian Biology,Volume VIII assesses selected aspects of avian biology. It is generally the conceptual descendant of Marshall's earlier treatise,"Biology and Comparative Physiology of Birds, but is more than simply a revision of it. This volume consists of two relatively lengthy, diverse chapters that focus on adaptive significance of coloniality in birds and fossil records of birds. In particular, this volume looks into group phenomena related to central place systems, that is, systems in which one or more individuals move to and from a centrally located place in the course of daily activities. It also addresses selective factors that have been suggested to explain why individuals should form colonies rather than disperse within the available foraging space. This book will be useful as a reference material for advanced students and instructors in this field of interest.
Author: Gary W. Kaiser Publisher: UBC Press ISBN: 0774859814 Category : Science Languages : en Pages : 402
Book Description
Birds are among the most successful vertebrates on Earth. An important part of our natural environment and deeply embedded in our culture, birds are studied by more professional ornithologists and enjoyed by more amateur enthusiasts than ever before. However, both amateurs and professionals typically focus on birds' behaviour and appearance and only superficially understand the characteristics that make birds so unique. The Inner Bird introduces readers to the avian skeleton, then moves beyond anatomy to discuss the relationships between birds and dinosaurs and other early ancestors. Gary Kaiser examines the challenges scientists face in understanding avian evolution - even recent advances in biomolecular genetics have failed to provide a clear evolutionary story. Using examples from recently discovered fossils of birds and near-birds, Kaiser describes an avian history based on the gradual abandonment of dinosaur-like characteristics, and the related acquisition of avian characteristics such as sophisticated flight techniques and the production of large eggs. Such developments have enabled modern birds to invade the oceans and to exploit habitats that excluded dinosaurs for millions of years. While ornithology is a complex discipline that draws on many fields, it is nevertheless burdened with obsolete assumptions and archaic terminology. The Inner Bird offers modern interpretations for some of those ideas and links them to more current research. It should help anyone interested in birds to bridge the gap between long-dead fossils and the challenges faced by living species.
Author: Storrs L. Olson
Author: Storrs L. Olson
Author: Storrs L. Olson
Author: Gerald Mayr
Author: 
Author: Gerald Mayr
Author: Bruce William Hayward
Author: Donald Farner
Author: Gary W. Kaiser
Author: Lance Grande
Author: