Microraptor hanqingi, new species from China.

[Don Ohmes <d_ohmes@yahoo.com>]

> Again, I actually like the idea - since you're the one who pointed it 
out here, I was hoping you had some suggestions for what we'd predict if 
tree-roosting was indeed important to paravians.

The idea was never advanced by me as a testable lifestyle for any 
particular fossil specimen -- that would be a "misunderstanding" -- but 
it falsifies the idea that an animal evolving flight in tree-down 
gliding-first mode will by evolutionary logic show "arboreal 
adaptations" in its skeleton -- beyond the basic capacity to climb a tree...

I suppose predictions made by tree-roosting might include 1) limited 
upstroke early on (that is, even after the appearance of a sophisticated 
gliding wing), 2) that the perching foot would appear subsequent to 
powered flight (full upstroke), not before -- and 3) the capability of 
climbing vertically.

One note -- controlled climbing up is easier than climbing down -- and 
in the hoatzin type wing-claw model, climbing down would appear to be 
problematic, which makes parachuting/gliding useful.

In any case, I am unsure that these are unique predictions, and would be 
useful in "proving" tree roosting -- although I suppose in sum they 
might be a start.

Given that the possibility of a tree-roosting lifestyle falsifies 
certain assertions about the relevance of "arboreal adaptions" to bird 
flight evolution, I think any statements that the "discussion" was not 
fruitful are wrong.

> If your assertion is, instead, that we'd see no difference in the 
fossil record between a case a fully "terrestrial" origin and a 
"terrestrial + tree roosting" origin [...]

Yes, that is my assertion, but relative only to pes morphology in small 
cursorial, feathered, vertical-climbing, etc, etc...

I would think a strict ground-up scenario might predict a full 
wingstroke early on, even when wings are rudimentary -- but suppose that 
to be debatable.

Foraging in a tree would necessarily alter the feet, by evolutionary 
logic -- but just sitting or sleeping in a tree will not necessarily do 
so, especially given a ground-foraging lifestyle and the attendant 
conserving of cursorial morpho-type.

> then I'm not sure what is being argued.

Good question.

You could comb through the various threads and find other people to ask 
-- apparently no paravians would or could roost in trees, sauropods and 
tall theropods would pluck them off branches like so many peaches, any 
"rooster" would fall off and die when sleep came (yet could pounce on 
prey from the same branch with great success), and my personal fave, 
sickle-type claws would shear through any branches they gripped like 
pruning shears.

Interesting stuff...