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Re: Doesn't George have a point?



Larry Dunn,
>but doesn?t George have a point when he says that the
>lack of a suitable known dinosaur ancestor of birds in
>the appropriate time period raises some really serious
>doubts as to the dinosaur ancestry of dinosaurs?


    George and I talked about this last week.  There is NOTHING known
immediately predating Archaeopteryx in the fossil record that could have
been a suitable ancestor.  If the absence of Jurassic dromeosaurs counts
aginst them being the ancestor of Archaeopteryx, then the exact same applies
to ANY other group; non-dromeosaur dinobirds, descendants of
Megalanacosaurus or Longisquama, or whatever.  How can someone use the
argument "dromeosaurs didn't leave a Jurassic fossil record, so they weren't
there", and then turn around and talk about birds being descended from
dino-birds (also with no Jurassic fossil record) or birdlike intermediates
between Megalanacosaurus and Archaeopteryx (also with no Jurassic fossil
record, or ANY fossil record).  Does that mean Archaeopteryx is descended
from nothing?  Its like investigating a crime with no witnesses, and saying
"so-and-so couldn't have committed this crime, because he wasn't seen doing
it."  You either have to...
1. Conjecture about completely UNKNOWN, hypothetical groups being present
before Archaeopteryx.
2. Extend the stratagraphic range of a KNOWN group forward or backward in
time to get it before
    Archaeopteryx.
    Well, the first choice isn't neccessary, because it just so happens that
just a few million years after Archaeopteryx we pick up the fossil record of
an amazingly bird-like group of theropod dinosaurs...
     If alien paleotologists come to Earth millions of years from now and
find the fossils of a Holocene chimp and a Pliocene australopithecene, I
wonder if they will think about the trends toward loss of upright posture
and reduced cranial capacity in the higher primates.

LN Jeff

Remember, a closed mouth gathers no foot
-Steve Post
********************
Jeffrey W. Martz
3002 4th St. #C26
Lubbock, TX
79415
(806) 747-7910







>I guess this is actually a question about the
>scientific method as it relates to paleontology.
>Doesn?t the formation of this hypothesis require that
>the temporal bit fall into place as well?  As I
>understand the facts, there currently isn?t any
>specimen of a suitable coelurosaur predating the
>earliest fossil birds.  Doesn?t that have any bearing
>on the formation of a hypothesis?  (Or is this wrong?)
>  Can scientists say, ?other things look very good for
>our hypothesis, but we?ll need to keep looking for an
>appropriately early ancestor,? and still have a valid
>hypothesis?
>
>And what is the status of the idea until the suitable
>piece of information comes along?
>
>This is not a rhetorical question, or a statement of a
>position.  It is a quest ... for the truth (dramatic
>music).
>
>
>=====
>Larry
>
>"I've been ionized, but I'm OK now."
>
>http://members.tripod.com/~megalania/index.html
>
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