Re: Archaeopteryx with bird book, was Re: Archaeopteryx flight

[Nick Pharris <npharris@umich.edu>]

Quoting Patrick Norton <ptnorton@suscom-maine.net>:

> Tim Williams wrote:
>
> > I can answer that question in more than one way.  Firstly, there are 
> > two separate families of vultures (Old World and New World) that 
> > evolved independently.  There is also the marabou stork, a 
> > scavenging bird that also has a bald head.  So, that's three 
> > separate examples of baldness associated with scavenging in large 
> > birds.<
>
> Although the old and new world vultures are veiwed as not sharing 
> recent common ancestors, the new world vultures are viewed as arising 
> from the stork lineage (see Sibley and Alquist, 1990). So this 
> narrows the list to two taxa of bald headed scavengeres, at most.

True (probably), but to the best of my knowledge, storks are not thought to be
primitively bald-headed (with reversal(s) to feathered heads in most 
species). So the marabou probably represents an independent acquisition 
of
bald-headedness.

Nick Pharris
Department of Linguistics
University of Michigan