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Re: Doesn't George have a point?



Larry Dunn wrote:

<What I'm asking is really simple. Is it in line with
prevailing standards of scientific analysis of
prehistoric life to hypothesize that birds are
dinosaur descendants when the dinosaurs the birds are
said to have descended from come after the first birds
in the known fossil record?

 [snip]

 ...and that may very well turn out to be true of
Dromaeosaurs as well. But as of right now, we don't
have such evidence. This is really quite a
process-oriented question.>

  I do not want to be drawn into the fossil-record /
phylogeny debate, as my views on it are still being
worked out as I peruse the literature and other
evidence of my own eyes. However, the question does
very much depend on the knowledge of both, and since
neither can at this time be obtained with any degree
of surety, merely a parsimony analysis or such at
best, it is not perhaps wise to try to ask whether a
particular hypothesis is better than another because
of one or the other of these quanta.

  Maybe a better question would be to ask the relative
completeness of the Jurassic record in recording
maniraptoriform fossils. Much appears to be
concentrated in the Kimmeridgian and Tithonian, at
Solnhofen and the Morrison strata, and this is in part
due to the concentrated excavations. As *Mymoorapelta*
has shown, you can still find large animals in
well-studied layers ... there's a lot, simply, that we
don't know, or may never know, about the geological
record.

  Earlier Jurassic strata is well-documented in the
Chinle Group and uppermost Karoo, of South Africa, and
Xiashaximiao of China, and these may also spare
small-theropod material for further study that have
not been previously documented, that may allow further
discussion. What I say, though, is that as currently
known, we should not try to forge ahead in a dark maze
with no lantern and no map.

=====
Jaime "James" A. Headden

  Dinosaurs are horrible, terrible creatures! Even the
  fluffy ones, the snuggle-up-at-night-with ones. You think
  they're fun and sweet, but watch out for that stray tail
  spike! Down, gaston, down, boy! No, not on top of Momma!

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