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Ma vs myr

>I wish y ou  guys would stop writing "myr" for million years.  In
>scientific notation the prefix "m" means     milli, so "myr" means
>thousanths of a year.  100 myr would be justd o ver a month. The
>correct way is  to use "M" for Mega or million.  And use the
>inernational "a" for annum, not the anglocentric "yr" for  year.

Actually, being even more pedantic, "Ma" can only be used for specific
dates, and not durations.  Thus, the Cretaceous began at 145 Ma and ended 65
Ma, but did not last 80 Ma, but 80 million years.  Unfortunately, "myr" is
often used for the latter, but hopefully someone will come up with a better

Thomas R. Holtz, Jr.
Vertebrate Paleontologist
Dept. of Geology
University of Maryland
Colege Park, MD  20742
Email:Thomas_R_HOLTZ@umail.umd.edu (th81)
Fax: 301-314-9661