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Re: pterosaurs, bats, flying theropods



Michael Habib (mbh3q@cms.mail.virginia.edu) wrote:

<True, but it is quite likely that bats predate the K/T.  Molecular 
dating suggests a Cretaceous origin, and the fossil record does to some
extent as well, given how early in the Cenozoic advanced bats appear
(including some extant genera in the Eocene).  Either Chiropterans have a
Cretaceous origin, or they underwent a massive diversification in the
Paleocene.>

  Hey, it happened to the whales in the Eocene, and that's with Paleocene
and Eocene ancestors that are reasonably known. Bats may very well have
their earliest ancestors in the Paleocene, and very bat-like archontans
like colugos (Dermoptera) exist that can be purported ancestors with
little change. We are looking for miracle specimens, the special fossil
that will confirm everything we are preconceived about regard bat
evolution. They are there, and likely the key regions will be Fayoum
(Fayum)-like in geology where we will have that special fossil show up. Or
we could have it and not know.

  Oh, molecules are not miraculous, and it does depend on theories of
genetic change having a morphological expression, and how much a set of
genes can express such. Most molecular dates do not take into account the
possibility of Eldredge and Gould's PE, for example, or that gene
evolution may occur at different rates with constraints at different times
in a single lineage.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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