Batrachochytrium dendrobatidis, ( ) also known as Bd or the amphibian chytrid fungus, is a chytrid fungus that causes the disease chytridiomycosis in amphibians. In the decade after it was first discovered in 1998, the disease devastated amphibian populations around the world, in a global decline towards multiple extinctions, part of the Holocene extinction. A recently described second species, B. salamandrivorans, also cause chytridiomycosis and death in salamanders.