Humans have no clue about anything that has happened millions of years ago.
The so called scientists are making up stories, assumptions, and extremely wild guesses about that topic, but they would never admit it.
For example, astrophysicists know very well how flexible time itself is. But when it comes to old ages in earth's history, all the estimates assume that everything has been working in exactly the same manner and speed as it does right now. And that's just one of the wild guesses.
But not too serious, right? 😆