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Re:Feathers for brooding, (was: So here it is... my paper...)



 
-----Original Message-----
From: David Marjanovic <David.Marjanovic@gmx.at>
To: The Dinosaur Mailing List <dinosaur@usc.edu>
Date: Saturday, January 13, 2001 2:21 PM
Subject: So here it is... my paper, open for discussion (very long; try to view it in maximum window breadth)
 
I think you make a good point about Archie not being on the "mainstream" to birds. I couldn`t agree more (I am of the opinion myself that it may have been on it`s way to becoming a secondarilly flightless form).
 
What I do question is the idea that feathers were first developed for the purpose of incubating a brood. I know this is a fairly wideheld opinion. (I believe I last heard it express on one of Paul Serenos websites, how "ideal" was the wing of Caudipteryx for incubating a nest). What I can`t see is why the feathers had to be arranged in such a neat linear fashion for insulating a nest. I can,however,see it as necessary for flight function which requires such prescision alignment to produce an overall aerodynamic shape to the wing, in this case, a strong indication of secondary flightlessness in Caudipteryx. It seems to me that for the purpose of incubating a nest, (if that were natures intent), a random arrangement of more plumulus feathery structures would suffice.
 
 
(snip)
        After that, some tetanuran invented lying on its eggs and holding them with its arms. The arms of the famous brooding Oviraptor and ?Ingenia skeletons all circle the eggs in a way that if they had borne wing feathers, they had covered the nests and shielded them from sun and rain (Hecht, 1998 <yes, HP Jeff Hecht who mentioned this hypothesis by HP Tom Hopp in New Scientist>). Apparently there was a strictly Darwinian advantage in lengthening the arms and the feathers: longer arms = more wing area = bigger nests = room for more eggs = more offspring."
 
May be a good argument, at least it sounds like one, doesn't it? =8-)
 
(snip)
 
I would argue that the requirement for a "larger nest" and hence room for "more eggs and potential offspring" would be more appropriate for a species that did >NOT< carefully brood and care for it`s young. A species that took the extra time to brood it`s young, would also tend to provide ample care and protection against predation, thereby necessitating >fewer eggs< and offspring, and in fact would not be able to provide such care for an excessive number of offspring!