Re: Microraptor also ate fish

[GSP1954@aol.com]

The problem is that there is no way to ever sufficiently understand the 
flight performance of microraptors. That it was a powered flier is the greatly 
superior hypothesis because it had so many adaptations for supporting fairly 
large arms muscles and anchoring the primaries, well beyond those found in 
Archaeopteryx which itself was beyond just gliding (I've discussed this in 
the literature and won't repeat it here because that is not the specific 
issue). 

But what we can never know is what was the specific flight performance of 
microraptors. Because we can never know the actual size and cellular 
configuration of the flight muscles. Big turkeys can take off vertically 
because 
they have huge, anaeroboic burst power flight muscles, which run out of power 
quickly so they can't fly far. Ducks also have large flight muscles, but they 
have to take off subhorizontally because they are configured to produce 
limited anaerobic burst power, and are optimized for sustained aerobic power, 
so they can cruise long distances. 

It is very unlikely that microraptors had the extreme burst climb 
performance seen in turkeys, or the long range ability of ducks. My guess would 
be 
that microraptors had limited powered flight abilities, including being able 
to take off from the ground. But could it climb well enough to get into tree 
canopies from the ground on a regular basis? Very possibly no, be we can 
never know. 

What I do know is that having examined a number of big format photos of 
Microraptor central toe claws that were kindly supplied to me, that they are 
(using the recent published data sets and my own on a large set of predaceous 
birds) more strongly arced than the claws of any livng bird that reguarly 
traverses ground by walking hither and on. Only birds with weakly curved 
central toe claws walk and run a lot (I've sampled them, including the 
raptors). 
So Microraptor either used flight as it's main means of moving about from 
one place on the ground to another (doubtful in view of probably limited 
powered flight abilities, and probable lack of many open spaces in the Johel 
forests) or was primarily an arboreal climber (very probably, considering it 
lived in apparently dense woodlands). 

GSPaul


In a message dated 5/1/13 5:24:45 AM, david.marjanovic@gmx.at writes:

<< Maybe what should be researched first is whether *M.* was capable of 

powered flight and whether it was capable of gliding. (And the same, 

actually, holds all the way to *Confuciusornis*.)


If it was capable of powered flight, it didn't need trees to take off. 

It used to be thought that the ability to take off from the ground is 

special and must have been the last step in the evolution of flight -- 

but,  >>

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