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Re: Precisely Dating The KT Boundary

The mass extinction of dinosaurs occurred about 66 million years ago, at the end of the Cretaceous Period (K) and the beginning of the Tertiary Period, known as the K-T boundary.<

Unfortunately, this is (a) wrong, (b) wrong, (c) wrong, and (d) all of the above. Not in terms of the dating, but in the nomenclature. As of 2004, there is no more Tertiary. It's gone, period. (So is Quaternary.) They were discarded because they were remnants of the really old time division into "Primary, Secondary, Tertiary, and Quaternary" periods. Now, for the Cenozoic, there are only the Paleogene (Paleocene-Oligocene) and Neogene (Miocene-Recent). Thus, there is no more K/T boundary -- there is only the K/P boundary. This was decided by the International Stratigraphic Commission, so it's not like it's just one person's opinion -- this is, a la the ICZN, the "rules" that stratigraphers must follow.

Rich wasn't wrong, of course, in his post -- he was just quoting the article, which either means that the author of the article got it wrong, or else (and I have a hard time believing this) the Earthtime people were unaware of the change.

Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@gmail.com

"Actually, it's a bacteria-run planet, but
mammals are better at public relations."
-- Dave Unwin