"In other words, they don't know WTF killed the dinos. And the don't really know when they lived, but they're sure they did. They think."
Yup. And after many more decades that will still be the situation because no one was there to see it for themselves.
There are lots of things I didn't see for myself. I never saw Thomas Jefferson. I've never seen the pyramids of Egypt, nor heard a single shot fired in the War Between the States. But I have no doubt that those things are/were real.
ML/NJ