The end of the Pleistocene Epoch was marked with steadily warmer temperatures and the great ice age glaciers that covered vast areas of North America were in retreat.
Except for a 1,000-year period when things once again suddenly got remarkably colder, the cause of which is a mystery that researchers of the period have argued over for years.
Geologically, the start of this period is marked by a “black mat” of organically rich soil. Below the mat is the evidence of late Pleistocene flora and fauna, including the very large animals that once roamed across North America: mammoth and mastodons, dire wolves, horses, short-faced bears and others.
Hmmm. Gonna have to read that. There will be questions on the exact timing of various extinctions.