[dinosaur] Dating of dinosaur age during history

Good day,




I seem to recall that at the beginning of the 20th Century it was believed 
that Tyrannosaurus was only about 3 to 8 million years old (and 
Protoceratops about 13 million years after 1920). Is there any table of age 
estimates for dinosaurs and how it was improved during the time? E. g. how K
-Pg boundary was dated from the 19th Century up to modern estimates of 66.0 
mya. I have seen that around 1950 it was thought to be some 75 to 70 million
years ago? Thank you in advance! Tom