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Re: Lemurs and Feathers
In a message dated 6/20/01 10:58:43 AM, email@example.com writes:
<<>The problem with underwater flight is lack of fossil evidence.<
I'll ignore that, like everyone else does :-> , given that the Jurassic
fossil record of pretty much all small terrestrial animals is extremely poor.
Yes, but those of us who don't ignore the fossil evidence just because the
early Jurassic sucks, see a preponderance of evidence implicating a gradual
theropod-to-bird transition. So don't count me among your "everyone else."
<<flight in air is apparently next to impossible with symmetrical wing
I don't think even Feduccia went that far, did he? Symmetrical components can
be assembled into asymmetrical structures. How does one PROVE that flight is
impossible based on symmetrical feathers? I don't believe it. Boeing uses
<<All recent flightless birds have symmetrical feathers, right? (In ancient
Egypt ostriches were the symbol of justice because their wing feathers are
perfectly symmetrical.) Same for *Caudipteryx*, right?>>
Y'know what? I'm starting to get really dubious about the use of the terms
symmetrical and asymmetrical. Is the preservation of Caudipterix really so
perfect that symmetry can be measured in its remiges to say, plus-or-minus
1%? I sincerely doubt that ANY feather is 100.0% symmetrical. I've seen too
many, and they're all curved left or right, and their barbs are longer or
shorter on the left or right, simply based on which side of the body they
originate from. Perhaps we should start talking about "subsymmetrical" to
suggest, "effectively symmetrical" or some similar term. In my mind, the
great debates about symmetry are pointless, because none of the structures
under discussion are actually symmetrical. I'll say it again: integumentary
structures are generally asymmetric.
Tracy Ford wrote:
<<So, when is the paper going to be out?>>
Dinofest 98? Never, I guess.
Our new one, maybe 6-12 months, depending on rejections, resubmissions -- you
know, the usual.
<<In your theory brooding was first, so it goes back to the first theropods?>>
Some fish and invertebrates brood.
<<Would Coelophysis brood? Did all theropods brood or just some? (I know not
all birds do, I think I heard that). So your telling us T. rex brooded? I
can't see that large an animal doing it.>>
Here's how. Rex sits down near (not on) the nest, in the three-point posture
seen in theropod trackways (two feet and pubic boot). Then Rex leans forward,
balancing weight with tail until belly contacts rim of nest. Then Rex gently
covers excavation/eggs/chicks with breast, puts arms in nesting-oviraptor
posture, spreads feathers, gets tight seal. Heat from heart warms babies. Not
that much different from the way Rex's second-cousin-twice-removed, Robin
Redbreast, does it.
<<I've seen several other dinosaurs in a 'brooding' position, but because
they aren't theropods brooding isn't thought about.>>
Yeah, there's a lovely Psittacosaurus from the Gobi that is in the oviraptor
posture without a nest. I wonder if it could have applied that posture to a
Thomas P. Hopp
Author of DINOSAUR WARS, a science fiction novel published by iUniverse
Now Humans are the Endangered Species! http://members.aol.com/dinosaurwars