Re: The ACTUAL flying Microraptor paper in PNAS

[Tim Williams <tijawi@yahoo.com>]

Phillip Bigelow <bigelowp@juno.com> wrote:


> > M. gui's feathered hindwings,
> > although effective for gliding,
> > would have seriously hampered
> > terrestrial locomotion.
> 
> 
> Couldn't tuck those feathers in when not needed, hmmm?
> I wonder how they came to that conclusion?


So do I, Philip; so do I.  This "conclusion" appears to be an assumption, 
entirely unfounded.


In their description of _Microraptor gui_, Xu et al. (2003) made essentially 
the same assumption as Alexander et al. (2010): that the long metatarsal 
feathers would be a hindrance to terrestrial locomotion.  Xu et al. even go far 
as to say "The metatarsus feathers are inconsistent with the suggestions that 
basal dromaeosaurs are cursorial animals", and that microraptors were "arboreal 
animals".  This seems more than a bit OTT.  Sure, _Microraptor_ probably 
couldn't run very fast, but that doesn't mean that it was non-terrestrial.


Peafowl (_Pavo_) are predominantly terrestrial, despite the males (peacocks) 
having to lug around that huge feathery train.  So an elaborate plumage doesn't 
necessarily preclude terrestrial habits.  Peafowl aren't exactly "cursorial", 
but they are hardly "arboreal" either.  Peafowl are omnivores that feed and 
nest on the ground, and live in forests.  Good cursorial abilities aren't much 
use in close habitat.


So in short: the presence of large hindlimb feathers in no way means that 
_Microraptor_ was predominantly or exclusively arboreal.  It probably spend 
some time up in trees; but the osteology strongly suggests that (like every 
other non-avian theropod) it was poorly adapted for arboreal locomotion.


Cheers

Tim