Short answers, pulled from the story.
The word Mesolithic means middle stone, a Greek term combining mesos and lithos. John Lubbock introduced the terms Paleolithic and Neolithic in 1865 while Hodder Westropp added the intermediate category called Mesolithic in 1866.
The period spans roughly 15,000 to 5,000 BP in Europe. In the Middle East it covers roughly 20,000 to 10,000 BP.
Microlithic technology defined the Mesolithic toolkit as composite devices made from Mode V chipped stone. These small lithics replaced heavy-chipped equivalents typical of the Paleolithic era.
Pottery appeared in North-Eastern Europe, Siberia, southern European, and North African sites between 9,500 and 5,850 BP. The earliest manifestation may lie around Lake Baikal in Siberia.
The Shigir Idol stands over five metres tall carved from a larch plank topped with a human head. Radiocarbon dating of Shigir idol to 11,500 years old clarified Central Asia importance only after 2015 understanding emerged regarding its role for later European cultures.