The technical definition of the Holocene has to do with the extinction of a snail species in Sicily.
Kenneth LacovaraWhen the dinosaurs go extinct and 75 percent of life goes extinct after a meteor hits the planet, that's an era boundary. That's when we change from the Mesozoic to the Cenozoic.
Kenneth LacovaraThe Anthropocene essentially would be the time of human influence on the planet. That's controversial though, because geology is a retrospective discipline. The rocks of the Anthropocene haven't been deposited yet, really.
Kenneth Lacovara