To help compare orders of magnitude of different times this page lists times between 1015 seconds (a petasecond) and 1016 seconds (32 million years and 320 million years) See alsotimes of other orders of magnitude.
36 million years -- time since end of Eocene Epoch and beginning of Oligocene Epoch; age of the Cercopithecidae (Old World primates) superfamily.
40 million years -- estimated period of time until Australia will collide with Asia; time since the age of the Catarrhini parvorder. Time since the evolution of the first canines.
49 million years -- time since the whales returned to the water.
60 million years -- time since the evolution of the first primates.