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*Longisquama* and Fossil "Ghost" Lineages -- Rehashing an Old Debate



Eric Lurio wrote:

<Closely related? The graptolites went extinct during
the Devonian. Cephalodiscus graptolitoides is
Quarternary. The time difference is immense.>

  There is nearly the entire Mesozoic between two
lineages of champsosaurus, a subject discussed in the
thread "Ghost Lineages"; subjectively, no length of
lineage or duration between appearances of lineages
can be held to factor in phylogeny. Incompleteness of
the fossil record is well documented, and the
appearance of morphologically ancient forms in
Holocene collections (including coelocanths and
dogfish) would put doubt on the assumption that, just
because there is no known intermediary or that the
fossil record doesn't preserved the idealized, does
not mean it doesn't exist. Assumption of phylogeny
should not therefore consider the stratigraphic record
as a determining factor, merely a subjective; see
Benton, 1999, and references therein (very extensive,
including work by Raup and others) that described this
incompleteness and use case examples in many groups
(mostly invertebrates). References were covered in the
DML posts, as well.

<Even if either you or I am right in this debate, the
fact still remains that Logismama(sic) and any
dinosaur are a thousand times more closely related
than graptolites and Cephalodiscus graptolitoides.>

  How? Quatify your comparison. Do not rely on
vagaries or generalities to uphold an hypothesis. And
besides, it's not a matter of who's right, but what
hypothesis best explains the evidence, and this is
quatified through testing. If you cannot discount what
Ron Orenstein cited, do not further dispute it without evidence.

=====
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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