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Re: Dinosaur article



   Opinions, please, especially in terms of the facts I've tried to use.  I
don't have references lying around so I may need correcting ... or even
better supported examples.

>Dec. 7, 1995
>
>Jeff: You say that I made "a factual error" when I stated that ostriches
>and touracos have claws on their wings.The fact that the hoatzin only has
>wing claws as a chick does not make my statement incorrect. Perhaps it
>would be useful to add in my article that the claws only appear on the
>young, but it doesn't change the fact that they DO have them.

   The statements that Ostriches and Touracos do not have claws and Hoatzin
young do are totally separate statements.  One is not used in any way to
prove or disprove the other.

>The South American hoatzin also has claws on its wings when young. And,
>contrary to what you stated, the ostrich also has claws on its wings; in
>fact it has THREE claws. I suggest that you and Ronald Orenstein
>(International Wildlife Coalition) check your facts. So, are claws on the
>wings evidence of a transition between reptiles and birds? Obviously not,
>for these birds are very much alive today.

   Technically, ALL birds have three claws ... they have simply been fused
into one unit.  Past that, I'll let Mr. Orenstein and others confirm or deny
whether Ostriches have claws, with references.

   I'm frankly confused as to why you think wing claws in extant birds
disproves reptilian ancestry.  The only thing I can figure is you're
laboring under the false notion that descendant forms cannot share
characteristics with ancestral forms, especially if those descendant forms
are extant.  I don't think any evolutionist has believed that for a century.

>You ask: "So what is Mononychus, dinosaur or bird?" The actual fossil
>material (not conjecture) indicates it is a dinosaur. What do you think it
>is?

   I have no idea.  I'm not familiar with Mononychus.  My problem with its
mention in your article is that it seems to come out of left field.  I don't
at all see how it is being used to further the argument that fossils do not
support evolution.

>>Paleontologists say that in order for a complete dinosaur to fossilize, it
>>had to be rapidly buried in large quantities of sediment. The contorted
>>appearance of many skeletons suggest burial of dinosaurs which died in
>>agony, or of freshly dead dinosaurs whose limbs were distorted by the
>>sediment load and rapid water current which carried the load. [The Tyrrell
>>paleontologists report that the ornithomimid was found in the "classic
>>death pose" with neck and tail dramatically curved.]

>You state:
>"I would prefer that the sentence "...suggest burial of dinosaurs which
>died in agony" be removed or rewritten.  The "contorted appearance" of many
>fossilized skeletons does not "suggest" that they died in agony.  Wording it
>this way plants the idea in the reader's mind that they did, indeed, die
>this way.  Nobody with any credibility believes this idea any more, and
>should be sunk like the bad science that it is."
>
>Just because the scientific majority believe something to be true, does not
>mean that it IS true. For example, during Galileo's lifetime, the
>scientific (and religious) consensus of the day believed that the sun
>revolved around the earth.They were eventually proven to be in error.
>
>How can Darwinian paleontologists be so "certain" that dinosaurs did NOT
>die in agony? Were they there to see any of them die?

   What evidence is there that they *did* die in agony?  Bottom line is that
there is a huge body of evidence that supports the principle that the "death
pose" is post-mortem drying of ligaments.  To my knowledge there wasn't a
huge body of evidence for the sun revolving around the earth, it was merely
an assumption believed by all.  It took Galileo making the first serious
studies of the universe to begin to unravel that belief.  I also seem to
recall that despite the outcome of Galileo's experimentation, many of which
were carried out before the disbelievers, and a sizable body of evidence,
people still refused to believe.

> My statement is worded in a tentative way, and I see no reason to change it.

   The reason to change it is because it allows "death by agony" as a viable
conclusion.  As long as the reader can be left with the idea that the
contorted appearance is due to dying in agony, whether through drowning
("Great Flood Theory"), suffocation or poison ("Impact theory" or "Vulcanism
Theory"), I'll object to it. 

>Let the reader
>draw his own conclusions. In fact you criticize me for not answering the
>questions that I raise....I would direct you to what Michigan State
>physiology professor Robert S. Root-Bernstein (an evolutionist) recently
>wrote, regarding his introductory course on evolution:
>
>"I encourage [students] to be skeptical---as long as their skepticism is
>based on logic and evidence....Questions are what drives science, not
>answers....Take nothing for granted, I counsel my students: that is what
>makes a scientist." ("Darwin's Rib", in Discover, September 1995,
>pp.38-41).

   I object to them because the reader is not given the "evidence" on which
to make the logical conclusion (or ask the logical questions) called for by
Mr. Root-Bernstein.

   For example:

>It is interesting that dinosaurs that had long slim legs, small lightweight
>bodies, and in general appearance look somewhat like birds, such as ostrich
>mimic Struthiomimus, were "lizard-hipped". Conversely, dinosaurs that look
>more like low-slung tanks than graceful birds (eg. Ankylosaurus) were
>"bird-hipped". Therefore, one question that should be put to dinosaur
>experts is: If dinosaurs evolved into birds, wouldn't we expect to see
>"bird-hipped" dinosaurs looking more bird-like rather than the reverse?

   Your question, "If dinosaurs evolved into birds, wouldn't we expect to
see "bird-hipped" dinosaurs looking more bird-like rather than the reverse?"
is preceded by factoids that someone not familiar with birds and dinosaurs
could easily assume are the whole story.  Readers are never given any more
evidence than a statement concerning the superficial appearance of "lizard
hips" and "bird hips."  The reader needs more information regarding what
dinosaurian "lizard hips" and "bird hips" are.  They need to know why the
names were chosen.  The reader needs much more information concerning the
anatomy and morphology of bird and dinosaur hips to even begin to ponder the
answer of such a question.  Taken with the rest of the paragraph, and the
theme and purpose of the article, the question comes off as "... So wouldn't
you expect birds to be related to bird-hipped dinosaurs?  Hmmm?  Hmmm?
Wouldn't they?  Evolutionists say they're not, so evolutionists are full of
it."  It's the only "logical" conclusion from the scant evidence presented.

>When presented with information that both supports and questions evolution
>and its underlying assumptions, students and the public at large can become
>better at thinking critically.

   And this article doesn't do it.  The information is, at best, incomplete.

>Now, referring to Archaeopteryx...Although Archaeopteryx has some features
>that are similar in morphology to those of reptiles, so what? It does not
>necessarily follow that Archaeopteryx was a transitional creature between
>reptile and bird.

   You are correct, it does not necessarily follow.  Convergent evolution
happens.  But taking the attitude of "so what" is nuts.  Similar morphology
is what defines relationships.  Dogs have hair, three bones in the middle
ear, and lactate.  "So what" you say?  It does not necessarily follow that
dogs are related to, say, cats that also have hair, three bones in the
middle ear, and lactate, you say.

>Even some evolutionists recognize that Archaeopteryx was a bird: L. Martin
>(1985, p. 182) concluded that "Archaeopteryx was a true bird." Colin Brown
>(1987, p. 78) concluded that "the creature was a true bird and not some
>kind of intermediate stage between reptiles and birds." Junker and Scherer
>(1992, p. 199) and Feduccia (1993) state that Archaeopteryx was surely a bird
>because of feathers that are identical to those of modern birds.

   Anything with feathers is, BY LINNEAN AND CLADISTIC DEFINITION, a bird.
However, feathers are a weak synapomorphy for birds, mainly because there is
no proof that certain creatures that are believed to be closely related to
birds did or did not have feathers.  Also, I seem to recall that
Archaeopteryx's feathers lacked a feature in modern feathers that allow
adjacent feathers to interlock.  This means that Archaeopteryx's feathers
were not identical to modern birds.  That has nothing to do with repitlian
ancestry, but bears mentioning since it was brought up.

   Additionally, and this is something that I've wanted to know since this
whole thread started, is just what is the definition of "reptile" being
used, and what is the definition of "transitional form" being used.  That's
one thing the article definitely needs, a definition of how these two terms
are being used.  These two words mean different things to different people.

>Views on what creatures were the ancestors of Archaeopteryx have changed
>over the years, with the prevailing view being that it descended from small
>running dinosaurs (coelurosaurian theropods). See Ostrom (1985) and Padian
>(1989).

   That is by no means universal, and I wonder if it is even the most
prevalent these days (your refs are 6 and 10 years old).  I am familiar with
Ostrom's beliefs (I've actually briefly discussed them with the man in
person, one-on-one), and the fact is that he is, or was, of the old school
that did not take into account arboreal dinosaurs due to their (assumed)
lack of representation in the fossil record.  These days, many
paleontologists, and, possibly, finally, Ostrom himself, take into account
the slim chances of arboreal forms fossilizing, and therefore are more
likely to buy the notion that Archaeopteryx descended not from cursorial
forms, but arboreal forms.

>But there are significant differences bewteen Archaeopteryx and
>coelurosaurian theropods:
>1. Archaeopteryx had feathers identical to those of modern birds, whereas
>theopods had none

   First, last thing I heard, Archaeopteryx's feathers are different than
modern birds.  The differences are slight (I've mentioned the one I'm
familiar with) but enough that I wouldn't use the word "identical."  Second,
how the hell does *anybody* know that theropods had no feathers?  Soft body
parts such as feathers and hair do NOT fossilize except under very specific
conditions.  I am aware of only one skin impression of a theropod dinosaur,
and it is NOT from one closely related to the supposed ancestor of
Archaeopteryx, or Archaeopteryx itself.  When somebody finds a confirmed
skin impression of a Dromaeosaurid, the dinosaurs considered to be the
closest relations of Archaeopteryx, this argument may have merit.

>2. Archaeopteryx had a hypertrophied furcula (fused clavicles);theropods do
>not have one

  In fact, Oviraptors are confirmed to have had furculae.  There's even a
picture of one in _The Dinosauria_.  Recent fossil finds, and reexamination
of old specimens, have shown that Allosaurids had furculae.  I do believe
Mononychus, which you stated was a dinosaur, had a furcula.  A recent
discovery of a new, gracile theropod had a confirmed furcula.

>3. Manus claws of Archaeopteryx differ markedly from those of predatory
>dinosaurs (Feduccia, 1993)

   In fact, the manus of Archaeopteryx is almost an exact scaled-down
version of the manus of the predatory Dinosaur, Deinonychus (Ostrom and others).

>4. Archaeopteryx had a fully reversed hallux, the large rear toe, with a
>strongly curved claw on the ungual phalanx, which is typical of modern
>perching birds and unlike any known theropod dinosaur (Feduccia, 1993)

   Recent discussion on the Dinosaur Mailing List indicates that the
orientation and function of the hallux has, until recently, been an
assumption of the preparator/exhibitor.  Apparently the articulation of the
hallux with the ankle and other toes allows for preparators to position the
hallux in both a forward and retroverted position.  Without a pricely and
perfectly articulated skeleton, placement of the hallux in certain theropods
is speculative.  Whether the hallux of Archaeopteryx was unlike any other
theropod has become, recently, a "bone" of contention.

>5. Although Archaeopteryx had teeth, the crowns of its teeth were
>unserrated, the waist present, the root expanded, and the tooth replacement
>resorption pit oval to circular. On the other hand, in the reptiles
>Pseudosuchia and Coelurosauria, the crowns were serrated, the waist absent,
>the root straight and unexpended, and tooth replacement resorption pit
>elongate (Brown 1987, p. 78)

   I can't speak too much on this topic as teeth have never been of much
interest to me.  However, I do know that the recent discovery of
_Archaeopteryx bavarica_ has shown that this species had tooth and root
morphology that was shared only by theropods and some basal archosaurs.

>Not only are there problems linking Archaeopteryx to theropods, there is no
>link from it to any modern birds. Martin (1985, p. 182) states:"
>Archaeopteryx is not ancestral to any group of modern birds. It has
>specializations in its tarsometatarsus and skull which show conclusively
>that it is on a side branch of avian evolution."

   I can't speak to that last statement.  But to the statement that there is
NO link to modern birds ... I have a file on my homepage listing more than
20 shared derived characteristics between Archaeopteryx and modern birds.  

>If this is so, where then
>are the alledged intermediates lying on the main branch?

   Who knows?  Birds don't fossilize especially well under even the best of
conditions.  We're lucky to have any bird fossils at all.  If it wasn't for
the feather impressions in the Solnhofen limestone, the significance of
Archaeopteryx may never have been known.

>Another question for Darwinists to ponder is: how could scales become
>feathers, and not only be useful in the intermediate stages, but provide a
>comparative advantage?

   That very same question has been bandied about for the last two weeks on
the List.  Wish I'd paid more attention now.

>In his book "Evolution: A Theory in Crisis" (Adler & Adler,1986) molecular
>biologist Michael Denton blows out of the water any notion that scales
>could evolve into feathers, given a million years, a zillion years, take
>your pick, since the structures of scales and feathers are ENTIRELY
>different. Jeff, have you ever seen pictures of scales and feathers taken
>with an electron microscope?

   I, too, have read studies that involve the relationship between scales
and feathers and the conclusions were not favorable.  I do not know what the
majority opinion on this is right now.  However, there seems to be an
assumption that bird feathers *had* to come from scales if birds truly
evolved from "reptiles."  The problem is that 1) there is no certainty that
dinosaurs, especially those considered to be ancestral to Archaeopteryx even
had scales; and 2) dinosaurs and other archosaurs had an amazing variety of
"things" growing in their skin.  Feathers could have evolved from just about
anything.

>If, after over a century of examining the fossil record, Archaeopteryx is
>the best single piece of evidence for macro-evolution (as many textbooks
>have claimed it to be) then what does this say for the entire theory?

   From my viewpoint, it's a damn good theory ... or, more correctly, theories.

   And I certainly don't know that Archaeopteryx is the best evidence ...
from what I understand it is certainly not the *only* evidence.


>Dinosaur paleontologists would do well to consider what law professor
>Phillip E. Johnson (University of California at Berkeley) says on the
>subject of fossil "evidence" for evolution: "The fossils provide much more
>discouragement than support for Darwinism when they are examined
>objectively, but objective examination has rarely been the object of
>Darwinist paleontology. The Darwinist approach has consistently been to
>find some supporting fossil evidence, claim it as proof for "evolution,"
>and then ignore all the difficulties." ("Darwin on Trial", 2nd edition
>1993, p. 86)

   And I bet "objective examination has rarely been the object" of
non-Darwinist paleontology as well.

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