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Re: feathers, hair and Compsognathus



Jeffrey Martz wrote (quoting me):

> > You said they look like overlapping *things*.  Based on the evidence that 
> > NO 
> > non-lepidosaur has overlapping scales, AND the fact that birds are 
> > theropods, 
> > AND this fossil is of a theropod, AND birds have feathers, AND feathers had 
> > to start evolving sometime or another; it is more logical to assume that 
> > these overlapping things are in fact feathers AND NOT overlapping scales
> 
>      Why couldn't overlapping scales develop by anaolgy?  Structurally, 
> it would be child's play compared to evolving a complex structure like a 
> feather.

It is equally unlikely for a non-lepidosaur to develop a derived lepidosaur 
trait, as it is for a non-archosaur to develop a derived archosaur trait, so 
no, they probably couldn't be overlapping scales.
 
>       Mantell might have made the following argument:  Based on the 
> evidence that NO known reptile except _Iguanodon_ had ridged, iguana like 
> teeth, AND no known reptile was known that looked anything like Iguanodon 
> is now known to look, AND the fact that iguanas (or at least Mantell's 
> stuffed specimen) had a horn on the nose, and the fact that Mantell's 
> _Iguanodon_ specimen was associated with a big, horn looking bone, AND the 
> fact that _Iguanodon_ was clearly a reptile, AND had iguana looking teeth; it 
> is most logical to assume that _Iguanodon_ was a huge close relative of the 
> living iguana. 

Wrong, wrong wrong!!!!!  Mantell was working with an absolute zero fossil 
record and tried to make inferences based on about ten bones.  With 
Sinosauropteryx, we are dealing with a huge fossil record showing this 
animal's placement.  I am also making assumptions based on logic and things I 
know are probably not likely to have occured (the presense of derived 
lepidosaur traits in an archosaur).  So, assuming that Sinosauropteryx was 
indeed feathered and did not posses these derived lepidosaur traits that some 
claim it had to have, is in fact the most logical thing to do.

Peter Buchholz
gpb6845@msu.oscs.montana.edu