Re: Protoavis?

[Jeffrey Martz <martz@holly.ColoState.EDU>]

> * _Protoavis_ is always reconstructed as a biped.  A bipedal animal
> older than six million years can be one of only three things: a
> dinosaur, a bird, or some member of a group as yet unknown to science. 
> Why is that third possibility never mentioned?  

     Poposaur/rauisuchids include several memebrs that may have been
partially or habitually bipedal. I know of one being worked on right now
that shows a number of very theropod-like adaptations probably related to
bipedality.

> informed one that exists.  So how did the lines get drawn as "it's 100%
> bird" versus "it's either a theropod or a chimaera"?  Is there no chance
> that _Protoavis_ is, say, a very early scion of the line that led to
> maniraptoran dinosaurs and through them to birds?

     Not likely considering it contains some features which actually
appear more bird-like then maniraptorian theropods.

> My personal feeling on _Protoavis_ is that it might be a bird, a
> theropod, a birdy theropod, or something else -- but if you want me to
> accept it as a bird, find me one with feather imprints.  Nothing else is
> going to clinch it.

      Feathers aren't the only diagnostic characteristics of birds.  More
complete remains, with or without feather imprints, may settle the
dispute.

LN Jeff
O-