Does this mean they didn't exist before now?
If the answer is no, does not finding something mean it's extinct?
Something to keep in mind next time you bump into an eco nazi.
fruser1: Does this mean they didn't exist before now?
No.
fruser1: If the answer is no, does not finding something mean it's extinct?
No. It could mean either of two things: That we simply haven't found it (again or yet) - or, that it doesn't exist / never existed.
Regards,