By the beginning of the Late Epipaleolithic (or Mesolithic), people began to move into the newly open areas northward, and develop larger, more sedentary communities. The large-bodied mammals humans had survived on for thousands of years had disappeared, and now the people broadened their resource base, hunting small game such as gazelle, deer and rabbit. Plant foods became a substantial percentage of the food base, with people gathering seeds from wild stands of wheat and barley, and collecting legumes, acorns and fruits. About 10,800 BC, an abrupt and brutally cold climate shift called by scholars the Younger Dryas (YD) occurred, and the glaciers returned to Europe, and forested areas shrank or disappeared. The YD lasted for some 1,200 years, during which time people moved south again or survived as best as they could.
