Re: The fossil record

From: Don Winterstein <dfwinterstein@msn.com>
Date: Thu Feb 02 2006 - 06:07:15 EST

"95% of the fossils (by number) consist of shallow marine organisms (e.g., corals, shellfish). ... Of the remaining 5%, 95% are all the algae and plant/tree fossils...."

Wise seems to be dividing fossils into peculiar categories. If he really means for the first category to cover primarily corals and shellfish, his first statement can't be right. Fossils of animals such as corals, shellfish and crinoids are indeed common, but fossils of microscopic marine organisms must considerably outnumber them. California has formations hundreds if not thousands of feet thick consisting primarily of diatom frustules, the diatoms' microscopic "skeletons." Many other marine layers such as limestones, fossil reefs and chalks have high percentages of microscopic marine fossils such as foraminifera. The Austin Chalk is a very large formation that underlies much of Texas and, I believe, extends also into Louisiana and possibly beyond. (I used to have easy access to maps of all this stuff!) The first website I looked at on this had the following comment:

"Over most of its range, the Austin Chalk is dominated by two interbedding end-member rock types, chalk and marl.... Tan to white chalk beds are composed of partly recrystalized, fragmented nannoplankton matrix having 5 to 25 percent foraminifers and whole or fragmented inoceramid pelecypods."

Five percent of forams over the entire Austin Chalk would give astronomical numbers, and the numbers of diatom frustules in California must also be astronomical.

It's relatively reliable to extrapolate between samples from diatomaceous and chalk formations, because the composition tends to be fairly uniform. It's more difficult to extrapolate for larger marine organisms, because their population densities depend strongly on proximity to reefs or shorelines. (David Campbell would know about this.) Macroscopic fossils of land plants and animals, on the other hand, are not preserved with any consistency, so it would be anyone's guess as to how many you're likely to find in a given formation.

Of course, Wise is just talking about the "fossil record." If that includes only known fossils, then it's pretty obvious that the microscopic marine fossils must vastly outnumber all the rest. (If you include shellfish, etc., with the microscopic fossils, the percentage must go considerably above 99.) If you leave out the microscopic fossils, Wise's scheme goes qualitatively in the right direction, but I can't comment on whether it's quantitatively correct. Who's done the counting?

Don

----- Original Message -----
  From: Carol or John Burgeson<mailto:burgytwo@juno.com>
  To: asa@calvin.edu<mailto:asa@calvin.edu>
  Sent: Monday, January 30, 2006 9:46 AM
  Subject: The fossil record

  The Nature of the Fossil Record

  "95% of the fossils (by number) consist of shallow marine organisms
  (e.g., corals, shellfish).

  "Of the remaining 5%, 95% are all the algae and plant/tree fossils
  (including the coal) and all the other invertebrate fossils (e.g.,
  insects).

  "5% of the 5% (or 0.25% of the entire fossil record) are the vertebrate
  fossils (fish, amphibians, reptiles, birds and mammals).

  "Only 1% of this 0.25% (or 0.0025% of the entire fossil record) are
  vertebrate fossils that consist of more than a single bone! (E.g., there
  are only about 2,100 dinosaur skeletons in all the world's museums.)"

  - Kurt Wise, "The Nature of the Fossil Record," ICR lecture.

  Are the quantifications above approximately true?

  Just wondering. Not that they prove anything.

  Burgy
Received on Thu Feb 2 06:03:34 2006

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