The olm was first officially recorded by naturalist Johann Weikhard Freiherr von Valvasor (more commonly known as simply Valvasor) in his 1689 book Glory of the Duchy of Carniola. He reported that olms were often washed out of their caverns during heavy rainfall, and that the local people believed them to be the offspring of subterranean dragons. He described the olm as, "Barely a span long, akin to a lizard, in short, a worm and vermin of which there are many hereabouts".









