A stadial of the Weichselian cold stage, dated to between 11,000-10,000 bp. The last glacial recession (13,000-6,000 years ago) was interrupted by this sharp advance. It takes its name from a tundra plant called Dryas octopetala, fossil remains of which are common in deposits of the stadial. It was most evident around the North Atlantic and coincided with an apparent temporary diversion of glacial meltwater from the Mississippi River to the St. Lawrence drainage system. It has been postulated that this discharge of cold, fresh water disrupted the Atlantic Ocean circulation system that warms the North Atlantic.