the Devonian-Carboniferous transition. At the end of the Frasnian Age in the later part(s) of the Devonian Period, a prolonged series of extinctions eliminated about 19% of all families, 50% of all genera[6] and 70% of all species.[citation needed] This extinction event lasted perhaps as long as 20 MY, and there is evidence for a series of extinction pulses within this period.