I am beset with dish pan hands from the last two days of turning lumps of grey mud into geologic time.  How does that work?  Our mud has turned up pretty foraminifera as well as calcareous NANNOfossils (i.e. really small ones) and the species of both groups come and go through a cycle of evolution and extinction.  We know about when the various species evolve and disappear so we can use their occurrences to tell time. Last night the fossils told us that the bottom of our first drill hole was in mud that was 5 million years old–about the age when our distant hominin ancestors separated from the chimpanzees and went off to the savannas to remake the planet.