Was a strain of Aspergilus Niger - http://news.nationalgeographic.com/news/2005/05/0506_050506_.... Same kind of mold you find in your kitchen on forgotten fruit, but probably this strain was different enough from ones Europeans had exposure and immunity to that it killed a few mildly immunodepressed explorers and a tourist. I remember even a documentary about some of it... kind of boring though.

Ancient Indian mythology is creepy as fuck though, got to agree - they even mention units of time of sizes like 8.64 billion human years and longer mentioned in scriptures more than 2000 years old... I mean, I imagine they got to that by playing with exponentiation and logarithms for the first time while trippin' on some 'shrooms... but that's still a good creepy basis for some alternate history tales :)

It's a theory although it seems that most experts are skeptical:

http://news.nationalgeographic.com/news/2005/05/0506_050506_...