On Tue, 05 May 1998 19:39:58 -0500, Glenn R. Morton wrote:
GM>Stephen, I have said all that I am going to say about Longisquama. I simply
>don't find it of profit to continue with you on these.
I am not surprised! Longisquama has not turned out to be as good an example
of "half- scales/half feathers" as you originally thought:
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Date: Sat, 04 Apr 1998 14:09:16 -0600
To: evolution@calvin.edu
From: grmorton@waymark.net (Glenn Morton)
Subject: half-evolved feathers
[...]
I just ran into the following data which contradicts one of the favorite
anti-evolutionary claims. The claim is as follows, Morris and Parker state,
"There are no true transitional forms (that is, in the sense of
forms containing incipient, developing or transitional structures
- such as half- scales/half feathers, or half-legs/ half wings)
anywhere among all the billions of known fossil forms." ~Henry M.
Morris and Gary E. Parker, What is Creation Science?, (El Cajon:
Master Books, 1987), p. 11
Feduccia and Wild relate:
"Megalancosaurus, in combination with Longisquama, a Lower
Triassic thecodont with featherlike scales and furcula, render
this group (basal archosaurs, including thecodonts) the most
liekly candidate for proximity to avian ancestry."~A. Feduccia
and R. Wild, "Birdlike Characters in the Triassic Archosaur
Megalancosaurus," Naturwissenschaften, 80(1993):564-566
It would appear that the antievolutionary claim is not verified by
observational data.
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Your problem was that you thought the long scales on the
back of Longisquama were the claimed proto-feathers but
it was the scales covering Longisquama's *body* which your
source Bakker claimed were the proto-feathers:
"LONGISQUAMA, a small animal whose fossil was discovered in
middle Triassic lake beds in Turkestan by the Russian paleontologist
A. Sharov, was a thecodont. Its *body* was covered by long
overlapping scales that were keeled, suggesting that they constituted
a structural stage in the evolution of feathers.* The long devices along
the back were V-shaped in cross section; they *may have served as
parachutes and also as threat devices*, as shown here. (Bakker R.T.,
"Dinosaur Renaissance," Scientific American, April 1975, Vol. 232,
No. 4, p68. Emphasis mine)
* your quote ended here.
"Did some of the thecodonts have thermal insulation? Direct evidence
comes from the discoveries of A. Sharov of the Academy of Sciences
of the U.S.S.R. Sharov found a partial skeleton of a small thecodont
and named it Longisquama for its long scales: strange parachutelike
devices along the back that may have served to break the animal's fall
when it leaped from trees. *More important is the covering of long,
overlapping, keeled scales that trapped an insulating layer of air next
to its body* [see top illustration on page 68]. These scales *lacked the
complex anatomy of real feathers*, but they are a perfect ancestral
stage for the insulation of birds." (Bakker R.T., "Dinosaur Renaissance,"
Scientific American, April 1975, Vol. 232, No. 4, p70)
"It would appear that the" *evolutionary* "claim is not verified by
observational data", and to date Morris and Parker are right.
Since you are always berating "Christian apologists" for failing
to admit when they are wrong, maybe you could in this case
practice what you preach and admit you were wrong about
Longisquama?
Steve
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Stephen E (Steve) Jones ,--_|\ sejones@ibm.net
3 Hawker Avenue / Oz \ Steve.Jones@health.wa.gov.au
Warwick 6024 ->*_,--\_/ Phone +61 8 9448 7439
Perth, West Australia v "Test everything." (1Thess 5:21)
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