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Re: Feathered Dragons: Studies on the Transition from Dinosaurs to Birds

Pete Buccholz wrote:

I would think that, at least in the case of _Microraptor gui_, the fact that
long feathers appeared on the legs all the way down to the distal metatarsus
argues strongly in favor of arboreal habits for _Microraptor_. Had _M. gui_
been terrestrial, I'd imagine the distal-most feathers would have been destroyed
in the process of walking on the ground

To add to that, the feathers appear adapted for aerial locomotion (probably gliding, although some - not me - have suggested it was a powered flier). It appears highly unlikely that _M. gui_ was capable of launching itself into the air from ground-level, thereby requiring a takeoff from an elevated platform (e.g., a tree branch).

Jaime Headden wrote:

Aside from this, absence of a reverted hallux in other theropods does not
preclude their being able to climb or be in a tree ... it only prohibits
"effective" perching and grasping on branches two-leggedly.

The hands of maniraptorans were probably able to be used in climbing - up until the point at which the manus was absorbed into a coossified carpometacarpus. Thus, these animals could climb in a "four-legged" fashion.

Arboreal maniraptorans did not need to *perch* in order to stay in the tree-tops, since all four limbs could be used to gain purchase on tree branches. Also, the modern hoatzin adopts a posture known as "sternal perching", in which the sternum is used to help support the body when perching. Maybe the first arboreal maniraptorans did this too.

This doesn't mean no other bird or other maniraptoran theropod (or even any small
coelurosaur) could climb or get into a tree for at least PART of it's habitus.

Indeed, the pedal phalangeal proportions support the hypothesis that certain maniraptorans (including _Archaeopteryx_) divided their time between the ground and the trees.



Tim

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