"Bacterial spores have recently been brought to public attention, following the use of these organisms for warfare purposes and the exciting report of viable 250-million-year-old spores (35).
Yikes! I read the article, it didn't say how they found them. I know they have found viable archeobacteria in the guts of insects trapped in amber.
I'm a bit spooked by something that old. Modern lifeforms might have lost all resistance.