YOURDOOM? As far as I know it doesn't just spread by opening mail, but maybe... Hmm, I check mail and there are no unknown messages...
History periods? Cool. I only thought that 60 million BC is not creatacerous anymore, it's (how it's called in english, damn) tri-something... hmm, dictionary claims it's "tetriary period". So I'll agree. Wink Creatacerous ended directly at 65 million BC (or 66, depending on what some scientists claim).
I see there will be linear story, if you travel from one period to another...
In 600 BC Rome wasn't that powerful yet...