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Re: Microraptor also ate fish



 On Tue, Apr 30, 2013 12:55 AM EDT Mike Keesey wrote:

>> Mortimer wrote: [ … ] their time in trees?  How strict/misleading are the 
>> osteological correlates we look for, basically.
>>

>Right, this stuff would be very interesting to know. 

I agree, but likely it is not knowable - what an animal is doing can over-ride 
time as a driver of morphology - as example, an animal that forages for lizards 
in the terminal branch environment would likely show evidence of that in the 
pedal extremities, even in the case where a small portion of it's day was spent 
doing so.

However,  M. gallopavo spends the night hours in trees, but forages, nests, and 
mates on the ground.

As a result, a paleontologist examining a turkey skeleton would look at the 
foot and conclude that this bird was losing it's ancestral  hallux because it 
was a cursorial ground dweller.

And excepting that turkeys spend about half their lives in trees, he or she 
would be correct. 

This the significance of the ground foraging, tree roosting (or sheltering, if 
preferred) lifestyle to the evolution of birdness - beyond the basic ability to 
climb a tree combined with a cursorial foot, it might leave no obvious mark on 
the skeleton, particularly if *all* foraging and nesting was done on the 
ground. 

 This in turn refutes the claim that a trees down path to powered flight in  
birds can be ruled out due to the lack of obvious arboreal adaptations (e.g., 
the opposable hallux) in pre-birds.