Did the earth experience over a dozen great mass extinction?

there were 11 mass extintions.1 Precambrian(Paleozoic)2 Cambrian,3 Ordovician,4 Silurian,5 Devonian,6 Carboniferous,7 Permian.(Mesozoic)8 Triassic,9 jurassic,10 Cretaceous.(Cenozoic)11 tertiary, 0 quaternary/today.