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RE: Ward dino book
> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu]On Behalf Of
> Botterweg, Rrp
> Another theory by Peter Ward! (after his views on Pleistocene extinctions and
> extraterrestrial life).
> Oxygen-depleted? I thought that much, if not most of the Mesozoïcum was
> characterized by higher rather than lower oxygen levels?!
> I read some figures about Cretaceous oxygen levels (R.Sloan in Dinofest
> International Symposium Proceedings, but there
> are several other references):
> Barremian/Aptian - 28%
> Cenomanian/Turonian - 35%
> Campanian/Maastrichtian - 31-35%
> The lowest numbers I found for the Cretaceous were 21-26%.
> Anyway, at least equeal to or higher than today.
There are several competing (and in some parts of the column, mutually
exclusive!!) models of global oxygen levels. The ones Ward
uses put levels in the early Mesozoic (at least) as lower than present.
Thomas R. Holtz, Jr.
Senior Lecturer, Vertebrate Paleontology
Department of Geology Director, Earth, Life & Time Program
University of Maryland College Park Scholars
Building 237, Room 1117
College Park, MD 20742
Phone: 301-405-4084 Email: firstname.lastname@example.org
Fax (Geol): 301-314-9661 Fax (CPS-ELT): 301-405-0796