Re: Deinonychus Morphological Variations within Ontogeny

[GSP1954@aol.com]

Essentially all deinonychosaurs including Archaeopteryx have a strongly 
laterally facing shoulder glenoid that allows a flapping motion of the arms. 
Some of this information has been in the literature well back in time, I saw 
it examining the Archareopteryx and Deinonychus specimens in the 80s. As I 
diagramed in PDW, it is also true of some basal theropods, such as 
Coelophysis. So there is no reason to doubt that dinobirds could flap their 
airfoils. 
Their glenoids did not face as dorsally as in more derived birds, so they 
probably could not elevate their wings fully vertically. That would have very 
probably limited aerial climbing performance -- including an inability to 
achieve vortex inducing wing clapping that pigeons for example use to help 
rapidly climb nearly vertically from a ground take off. 

GSPaul</HTML>