I remember sitting with Jan Z, David Grinspoon, Clément Vidal, Jim Gates, David Baker, and several others at dinner at the Anthropocene Conference held at The Big History Institute at Macquarie U in Dec 2015.

Jan asked each of us what we thought was a "marker" for the Anthropocene. We all pitched in our ideas. For my money, I thought the radionuclide signature from open-air nuclear testing in the 1950s was so analogous to the iridium anomaly at the K-T Boundary (which my fellow Big History Association Board member Walter Alvarez had co-discovered in 1980), that that was what I thought it should be. I mean, it's there in the rocks for a VERY long time, right?

Jan said that the Working Group were actually considering that marker seriously. Unfortunately, they were not looking seriously at one of his observations about "Anthropocene Chicken" -- that the size of chicken skeletons had markedly increased during recent times, especially the 20th Century CE. He did mention it in his talk the next day, which is the second one in the playlist: