Re: Origin of feathers

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-29 03:05:56 EDT, Patrick.Norton@state.me.us writes:

<< Glad you reminded me. The long bony tail of Archeopteryx contributed far   
 more to drag than lift and would therefore have increased the sinking   
 rate while gliding.  The feathers on the tail of Archeopteryx probably   
 reduced that drag somewhat while in flight, but the primary aerodynamic   
 function of the tail feathers was, as it is in modern birds, to provide   
 effective rudder and braking control. >>

The only way to answer this question is to build a model of Archaeopteryx and
see how it flies. Do some wind-tunnel work. Tails do contribute drag, no
question, but the tail of Archaeopteryx is not like the tail of any living
birds, and it would be premature to accept your statements without some other
supporting evidence. In the fossils, the tail is of a size comparable to the
wings, and I don't think this is accidental. The tail feathers are apparently
horizontal and have a positive dihedral angle, for lift, not vertical, like a
rudder or fin. If Archaeopteryx was more a glider than a flapper, its tail
would seem to be ideal for maintaining aerial stability.