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Re: Microraptor hanqingi, new species from China.
> > But if you're a theropod, and you want to spend a large
> > part of your life sitting on boughs or branches, you need to have a
> > way of holding on.
> This is an active hypothesis, and requires evidence.
> And good luck on that -- it is mechanically incorrect relative to mere
> sitting or even standing on large, more or less horizontal
> branches/crotches by even inanimate objects, much less well-clawed
> theropods that presumably had reasonably competent balancing systems --
> "large branch" being defined as relatively rigid, and significantly
> larger in diameter than the contact point upon which the object or
> theropod balances.
> Moreover, there is no obvious selective path to a perching foot in the
> presence of active ground-foraging, the absence of active in-tree
> foraging, and/or exploitation of small, flexible branches, such as are
> found in the terminal branch environment.
Who cares about "obvious"? :-) We've discussed the Fowler et al. paper in PLoS
ONE about the prey-grasping function of the dromaeosaurid foot. That's a good
starting point for a branch-grasping foot (even though it _isn't_ a
branch-grasping foot itself).
I think sleeping in trees came next-to-last, followed only by nesting in trees.
That's because to sleep in a tree, you need a way to hold yourself in there
_while sleeping_. That can be a specialized foot, a big hole in the tree, or a
nest; ways of building nests in trees may not be very easy to evolve, and
finding holes big enough for anything the size of *Archaeopteryx* or
*Xiaotingia* or *Anchiornis* or any kind of *Microraptor* is difficult. -- I'm
sure I've overlooked other possibilities. What are they?