Do you have any text that back this up? I don't mean some university course that I need to attend. Just some intelligent fact that explains how you can arrive at a date like 75 to 85 million years?
You do rumealize that that is a huge amount of time previous to any recorded history, previous to any humans, previous to any written record. It is actually a number someone predicted, extrapolated, assumed or guessed. It is un testable as nobody was here to view it, nobody was there to record it and there is no possible way you can measure the time that hummingbirds morphed, evolved or hatched for the first time, with any accuracy whatsoever.
You can site the "geologic column" yet it has trees growing up through it. You can site carbon dating, yet it is only accurate to 50,000 years. You can site fossil data, yet fossils have been shown to form in 3 months in a laboratory setting. Given that we can throw out any date on a fossil's age. Given this, your 75 - 85 million years is hyperbola.