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Re: W. D. Matthew's _Dinosaurs_

On 7/16/07, tholtz@geol.umd.edu <tholtz@geol.umd.edu> wrote:
> On 7/14/07, Michael Mortimer <mickey_mortimer111@msn.com> wrote:
>> Ah, the Comanchic and Eogene periods.  And the KT event only 3.1 Mya.  I
>> didn't realize such things were believed in 1915.
> I've never heard of these before, and can't seem to find a history of
> either term on the web. Are these older names for certain units (Early
> Cretaceous, Paleocene) or do they reflect erroneous ideas about
> correlated strata?

The former. Some authors were still using "Comanchean" in the mid-20th
century, and the USGS (among others) were very late to formerly recognize
the Paleocene.

Ah. Given that the Cretaceous is almost as long as the Triassic and Jurassic combined, dividing it into two periods makes a lot more sense. (Too late now, though....)

Mike Keesey