Discoveries in the past quarter century have substantially changed the view of geologic and paleontologic events immediately prior to the Cambrian.
Dates are slightly uncertain with differences of a few percent between various sources being common.
It seems to me that the way I have seen things, the Neogene and Paleogene are subdivisions of the Tertiary when it is used, and of the Cenozoic when it is not. I personally like the latter better, but either way the above seems a bit confusing.