it's a unit of geologic time

That would be a new unit in the geologic time scale that stretches back more than 4.5 billion years,or ever since the Earth took shape.Modern humans may be on par with the glaciers behind various ice ages or the asteroid that doomed most of the dinosaurs.What is an epoch?Most simply, it's a unit of geologic time.There's the Pleistocene,an icy epoch that saw the evolution of modern humans.