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Re: climbing dromaeosaurs and friends



Why bother having a retro hallux >for prey manipulation< when the forelimbs were already well adapted for this purpose?<<<

Because small early fliers would have to grasp their prey as they ransitioned from flight-pursuit to tackling their prey so they can properly attack it. This pedal use is similar to falconiformes, i.e. prey grasping an maniputation, but the actual hunting style would be very different. Early birds are not, after all, falconiformes. But regardless of the reason, that's what the data shows.


Retro hallux first appears in ceratosaurs, which strongly suggests that the common ancestor of ceratosaurs and birds was a fairly good flier that had found having a grasping/perching foot highly adaptive: distally positioned retro hallux occurs in all theropods at ceratosaur grade or above.<<<

Which certatosaurs are you refering to? Certainly well reserved Ghost Ranch Coelophysis didn't have a retroverted hallux. I believe the hallux is preserved in Eoraptor, did anyone notice its orientation?
I should point out that my model is incompatible with the BCF theory. If further evidence supports BCF, then my model for the evolution of flight will be wrong, although Archeopteryx's pedal morphology will still be most consistent with prey manipulation.


Scott
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