A transitional turtle

Glenn R. Morton (grmorton@waymark.net)
Wed, 03 Jun 1998 18:03:48 -0500

First and second occurrence transitional form

There is a new transitional turtle which was recently reported in Nature.
The relevant part of the report is as follows:

"A marine vertebrate with a terrestrial ancestry has body fluids that are
much less salty than sea water, so an unprotected vertebrate immersed in
the sea runs the risk of dehydration. Water can be replaced by drinking sea
water. This raises the saltiness of the body with respect to the sea, so
there can be no net gain of water unless the salts are excreted in a
solution at least as concentrated as that of sea water. The kidneys of
marine reptiles, such as turtles, do not have this concentrating power:
without other methods of voiding excess salt, a marine reptile cannot eat
salty food or drink sea water without becoming dehydrated in the midst of
"Marine life is simply unliveable unless an animal solves the salt
problem. This 200-mm-long, 110-million-year-old fossil marine turtle,
described by Ren Hirayama on page 705 of this issue (Nature 392,
705-708;1998), has taken this lesson on board. The creature, which comes
from the Lower Cretaceous Santana Formation of north-east Brazil, extends
the fossil record of marine turtles back ten million years. The turtle is
primitive in the sense that the bones in its wrists, ankles and digits have
not become consolidated into rigid paddles. In other words, its feet would
have looked more like those of freshwater terrapins than fully seagoing
"Its salt-excreting arrangements were, in contrast, far less haphazard.
Marine turtles have lachrymal glands (each one larger, in some cases, than
the brain) modified to excrete a concentrated salt solution. The skull of
the Santana turtle shows evidence that it had enormous salt glands around
the eyes. In which case, the evolution of salt-excreting glands preceded
that of rigid paddles. The salt glands were the turtles' passport back to
the sea." ~ Henry Gee, "the Eyes Have It," Nature, 392(1998):651.

There are several important points to be noted here. First, this data
supports the predictions of the evolutionary viewpoint, not the
expectations of progressive creation or special creation. Turtles are
originally land creatures with feet adapted for life on land. The earliest
turtles ( found in the lowest or oldest rock layers) are found in the Late
Triassic. (Eugene S. Gaffney and James W. Kitching, "The Most Ancient
African Turtle," Nature, 369, May 5, 1994, p. 55).

Evolution would predict that if land turtles became marine, the feet had to
turn into flippers, and the salt problem must be accounted solved.
Progressive creation makes no such predictions since the marine turtles
would be created, supposedly adapted for life in the sea while the creator
would have created land turtles with no ability to handle salt and land
adapted feet. So what we find is that the earliest known turtle supports
the predictions of evolution not PC or special creation. Why is it that
this is so often the case? Could it be that evolution is true?

Secondly, many on this list will reject this as a transitional form. But
their rejection will most likely be based upon the idea that evolution MUST
be gradational or that this is still a turtle. Considering that most
biologists no longer believe in form of gradualism that Darwin advocated,
arguing against gradualism seems like arguing against humors, miasmas and
geocentricity. The objection that this turtle is still a turtle would be
less effective in this case because we are talking about the transition
from a land turtle to a marine turtle. The turtle's morphology is changing
in a mosaic style similar to the pattern seen in the fish/amphibian

With many of the transitional fossils what happens is that one body part
will change, then later another and then another. This is a mosaic type of
evolution-sudden jumps in the morphology of a body part. This can be seen
in the occasional 3 toed horses or 6 fingered people born even today.
There is no transitional form between polydactyly and the normal form, if
by transition one means a morphing of the form from one to the other. There
are either 3 toes or 1 toe but not a 2.5 toed horse. A person has 5 fingers
or 6 but not 5.375 fingers. The fish to amphibian transition is exactly
like this ( see my web page on this issue
http://www.isource.net/~grmorton/transit.htm ). The skull bones evolved
first in the fish with no lungs which preceded Panderithys.

Panderichthys-378 MYR-skull bones, upper parts of the limb bones(humerus,
radius ulna femur tibia and fibula), gills and lung 4 fins where the legs
would be.

Fish similar to Sauripterus- 370 MYR 8 fingers instead of fins

Elginerpeton 368 MYR-changes to shoulder girdle for better upright posture

Ichthyostega 363-MYR-7 digits on back leg, lungs and gills

Acanthostega 363 MYR-8 digits on front 7 on back. lungs and gills

Amphibians 340 MYR-no gills only lungs, 5 digits on each foot.

At each step a previous form was modified. Progressive creation must have
the creator create each successive step with only minor modifications over
the previous model of animal. This makes PC look like evolution.

What does this mean in the creation/evolution area? It means that unless
progressive creationists are willing to say that the progressive creation
is accomplished by the creation by God of a new form which only differs by
a single trait from the previous form, followed thousands of generations
later by another divinely created species which once again has only one
other body part changed, then the above data do not match the expectation
of progressive creation. If one must place progressive creation into a
form in which it differs not one whit from evolution, why would one stay
with progressive creation? The only reason I could think of would be for
philosophical reasons, not because the paleontological data supports it.

For an interesting article on the possible origin of turtles see:
Michael S. Y. Lee, "Correlated progression and the origin of Turtles,"
Nature, 379, Feb. 29, 1996. p. 812-813

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