"Terra Australis Ignota" (Latin, "the unknown land of the south") was a hypothetical continent appearing on European maps from the 15th to the 18th centuries, with roots in a notion introduced by Aristotle. It was depicted on the mid-16th-century Dieppe maps, where its coastline appeared just south of the islands of the East Indies; it was often elaborately charted, with a wealth of fictitious detail. The discoveries reduced the area where the continent could be found; however, many cartographers held to Aristotle's opinion, like Gerardus Mercator (1569) and Alexander Dalrymple even so late as 1767 argued for its existence, with such arguments as that there should be a large landmass in the Southern Hemisphere as a counterweight to the known landmasses in the Northern Hemisphere. As new lands were discovered, they were often assumed to be parts of this hypothetical continent.