Wilkinson's pterosaur wings

["Unwin, Dr D.M." <dmu1@leicester.ac.uk>]

Dear All,
 
I just happened upon Matt Wilkinson's latest paper in the Journal of 
Evolutionary Biology (details below). 
Have not had time to read it in detail (pedagogical duties), but it seems to be 
an excellent piece of work
and the clearest exposition of the basic mechanics of pterosaur wings published 
so far. 
 
Incidentally, Matt and colleagues (including myself) are busy with yet another 
paper on the pterosaur forewing and will be presenting on this at the 55th 
Symposium of Vertebrate Palaeontology and Comparative Anatomy, to be held this 
year in Glasgow between Monday 27 August and Saturday 1st September. (See 
www.svpca.org for more details).   
 
Anyway, here are the details of Matt's paper:
 
Sailing the skies: the improbable aeronautical success of the pterosaurs 

Matthew T. Wilkinson 

Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 
3EJ, UK 

e-mail: mtw21@cam.ac.uk 

Accepted 28 February 2007 

Abstract
 
Pterosaur wings bore a striking resemblance to sails, having a bony spar at the 
leading edge, formed by the forelimb and one enormously elongated digit, and an 
elastic wing membrane. Such simple wings would be expected to have performed 
badly due to excessive deformation, membrane flutter and poor control 
characteristics. Here I discuss how certain anatomical features, specifically a 
forewing membrane in the inner part of the wing and a system of fibres embedded 
in the distal part, may have countered these shortcomings. The forewing, 
supported by the unique pteroid bone, would have reduced the wings' geometric 
twist, and has been shown in wind tunnel tests to improve membrane stability at 
low angles of attack and dramatically increase the maximum lift coefficient at 
high angles of attack. The function of the fibres is poorly understood, but it 
is suggested that they improved membrane stability and optimised twist nearer 
the wingtips. 

Key words: actinofibrils, aerodynamics, aeroelasticity, propatagium, pteroid, 
pterosaur flight, sails, wing membrane.

First published online May 8, 2007
Journal of Experimental Biology 210, 1663-1671 (2007)
Published by The Company of Biologists 
<http://www.biologists.com/web/cob_copyright.html>  2007 
doi: 10.1242/jeb.000307
 
Cheers,
 
Dave