Q: Does the Catholic Church agree with geologists about the age of the earth? Why would God create dinosaurs, have them roam the earth for millions of years and then create human beings? Why doesn’t the Book of Genesis explain this? What does the Catholic Church teach about this?
A: I leave the issue of how old the earth is to scientists, who have frequently revised their estimates within my lifetime. The people whom God inspired to write the books of the Bible may not have known about dinosaurs. Did the Emperor Marcus Aurelius, who died in 180 A.D., know about them? All the books of the Bible were written by that date, with the Book of Genesis finalized almost 700 years earlier.
According to the Oxford English Dictionary, the word dinosaur entered the English language only in 1841. You ask why God would create dinosaurs before creating human beings. Who are we to dictate to God about such things?
It is important that we accept the Bible for what it is (the self-revelation of God) and not complain that it is not something else (an encyclopedia of all knowledge). Even encyclopedias need to be updated as our knowledge grows!
The opposition between religion and science is really a false opposition because a single God stands behind both of them. At times, some religious people have claimed too much (the sun moves around the earth because the Bible presumes that). At other times, a few scientists have claimed too much (scientific research is not subject to moral limits).
In heaven, you can ask God about the decision to create dinosaurs before human beings.