What does 300m years mean? Is that 300 or 300 Million?
I agree that the continued use of the abbreviation in the article itself is bad journalism.
Where? I can find no reference to this.
"M" was originally an abbreviation for "mille," which is French for "thousand" (by way of Latin origins). Traditionally speaking, one "M" means thousand, and "MM" means thousand-thousand, or million.
Example:
http://blog.accountingcoach.com/what-does-m-and-mm-stand-for...