The University of Southampton
University of Southampton Institutional Repository

Forelimb posture in dinosaurs and the evolution of the avian flapping flight-stroke

Nudds, Robert L. and Dyke, Gareth J. (2009) Forelimb posture in dinosaurs and the evolution of the avian flapping flight-stroke Evolution, 63, (4), pp. 994-1002. (doi:10.1111/j.1558-5646.2009.00613.x).

Record type: Article


Ontogenetic and behavioral studies using birds currently do not document the early evolution of flight because birds (including juveniles) used in such studies employ forelimb oscillation frequencies over 10 Hz, forelimb stroke-angles in excess of 130°, and possess uniquely avian flight musculatures. Living birds are an advanced morphological stage in the development of flapping flight. To gain insight into the early stages of flight evolution (i.e., prebird), in the absence of a living analogue, a new approach using Strouhal number inline image was used. Strouhal number is a nondimensional number that describes the relationship between wing-stroke amplitude (A), wing-beat frequency (f), and flight speed (U). Calculations indicated that even moderate wing movements are enough to generate rudimentary thrust and that a propulsive flapping flight-stroke could have evolved via gradual incremental changes in wing movement and wing morphology. More fundamental to the origin of the avian flapping flight-stroke is the question of how a symmetrical forelimb posture—required for gliding and flapping flight—evolved from an alternating forelimb motion, evident in all extant bipeds when running except birds.

Full text not available from this repository.

More information

e-pub ahead of print date: 14 January 2009
Published date: April 2009
Keywords: bird, locomotion, morphology, strouhal number, wing
Organisations: Ocean Biochemistry & Ecosystems


Local EPrints ID: 205177
ISSN: 0014-3820
PURE UUID: 70eb221d-2dd2-423c-9657-6bc3e709efa3

Catalogue record

Date deposited: 07 Dec 2011 10:17
Last modified: 18 Jul 2017 11:05

Export record



Author: Robert L. Nudds
Author: Gareth J. Dyke

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.