Confuciusornis:
When looking at this type of picture notice that the feathers in the wing's leading edge exhibit the exact same form as the pterosaur long finger.
The feathers extend where the pterosaur finger used to extend.
This would be the exact result when the finger was shortened.
The change is not that great, facilitated by "facilitated variation".
For reference:
ReplyDeleteNaish:
http://scienceblogs.com/tetrapodzoology/2009/06/10/birds-come-first-no-they-dont/
"The fact that long remiges have now been documented in oviraptorosaurs, dromaeosaurids and other maniraptorans shows that feathered arms essentially the same as those present in basal birds evolved somewhere round about the base of the oviraptorosaur + paravian clade, and there is no evidence that wing-like arms were present in more basal coelurosaurs, nor in other theropods, or other dinosaurs, or other archosaurs. Why did long remiges evolve among maniraptorans? We don’t know."
For reference:
ReplyDeletehttp://9e.devbio.com/article.php?ch=16&id=161
"There are other differences between dinosaurs and birds: Dinosaurs had serrated teeth, while birds have peg-like teeth. Bird feet have reversed toes used for perching in branches--something no dinosaurs has been seen to have. Meanwhile, dinosaurs had a characteristic joint in their lower jaws for grasping prey--something never found in birds."