Extinction intensity:
Apparent extinction intensity, i.e. the fraction of genera going extinct at any given time, as reconstructed from the fossil record. (Graph not meant to include recent epoch of Holocene extinction event)
X-Achse: Jahre von Christi Geburt (in Millionen)
In the past 550 million years there have been five major events when over 50% of animal species died.
Quelle:
http://en.wikipedia.org/wiki/Mass_extinction
Periods are coloured as per the Paris system