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Re: Theropod cranial shape paper



From: Ben Creisler
bscreisler@yahoo.com
 
Just in case some people had the content of the message blocked, here's the ref 
again with the abstract in plain text: 
 
BRUSATTE, S. L., SAKAMOTO, M., MONTANARI, S. and HARCOURT SMITH, W. E. H. 
(2011) 
The evolution of cranial form and function in theropod dinosaurs: insights from 
geometric morphometrics. 
Journal of Evolutionary Biology (advance online publication)
doi: 10.1111/j.1420-9101.2011.02427.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2011.02427.x/abstract
 
Abstract
Theropod dinosaurs, an iconic clade of fossil species including Tyrannosaurus 
and Velociraptor, developed a great diversity of body size, skull form and 
feeding habits over their 160+ million year evolutionary history. Here, we 
utilize geometric morphometrics to study broad patterns in theropod skull shape 
variation and compare the distribution of taxa in cranial morphospace (form) to 
both phylogeny and quantitative metrics of biting behaviour (function). We find 
that theropod skulls primarily differ in relative anteroposterior length and 
snout depth and to a lesser extent in orbit size and depth of the cheek region, 
and oviraptorosaurs deviate most strongly from the "typical" and ancestral 
theropod morphologies. Noncarnivorous taxa generally fall out in distinct 
regions of morphospace and exhibit greater overall disparity than carnivorous 
taxa, whereas large-bodied carnivores independently converge on the same region 
of morphospace. The distribution of
 taxa in morphospace is strongly correlated with phylogeny but only weakly 
correlated with functional biting behaviour. These results imply that 
phylogeny, not biting function, was the major determinant of theropod skull 
shape.