Oh dear, jr, T-Rex was a creature that never knew what day it was, and did not survive to inform us of anything.
you need to study the issue of creation according to the Holy infallible Scriture here:
Kolbe Center for the Study of Creation
https://www.kolbecenter.org/
The Church has never infallibly defined whether the world was created only a few thousand years ago or several billion years ago. The Church has infallibly determined that the Universe is of finite age (i.e., that it has not existed from all eternity). And that Universe was created out of nothing.
As for Dinasours or other creatures, the Church does not have an official position on where different life forms developed over time. It says if they did, it was done under the **guidance of God***.
I have read articles from the Kolbe center and consider them a good source. And unlike Bergolio and the Vatican II sect, I take Genesis literally.