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The origin of the avian flight stroke; a kinematic and kinetic perspective

Stephen M. Gatesy and David B. Baier
The origin of the avian flight stroke; a kinematic and kinetic perspective
Paleobiology (September 2005) 31 (3): 382-399


Flying birds flap their wings to generate aerodynamic forces large enough to overcome weight and drag. During this behavior, the forelimbs are displaced and deformed in a complex, coordinated sequence of movements collectively known as the "flight stroke." Despite an influx of relevant fossil material and new functional insights from extant birds, the historical origin of the avian flight stroke remains poorly resolved. Potential behavioral precursors have been identified primarily on the basis of kinematic resemblance--similarity of movement irrespective of underlying mechanisms. We discuss fundamental issues of motion analysis that are frequently overlooked by paleontologists, and conclude that a purely kinematic approach is insufficient. Consideration of kinetics, the forces responsible for motion, offers a more complete picture of flight stroke evolution. We introduce six kinetic components that interact to determine a limb's trajectory. Phylogenetic mapping reveals that forelimb loading patterns have undergone at least two major transitions on the line from basal archosaur to modern bird. Using this kinematic and kinetic perspective, we offer four specific criteria to help constrain and evaluate competing scenarios for the origin of the avian flight stroke.

ISSN: 0094-8373
EISSN: 1938-5331
Serial Title: Paleobiology
Serial Volume: 31
Serial Issue: 3
Title: The origin of the avian flight stroke; a kinematic and kinetic perspective
Affiliation: Brown University, Department of Ecology and Evolutionary Biology, Providence, RI, United States
Pages: 382-399
Published: 20050901
Text Language: English
Publisher: Paleontological Society, Lawrence, KS, United States
References: 85
Accession Number: 2005-062985
Categories: Vertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus.
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Abstract, Copyright, The Paleontological Society. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 200521
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