This film starts out with an odd premise. Putting a twist on the Planet of the Apes plot, instead of earth astronauts ending up in the past or future of this planet, the Earth is visited by space travelers from a different planet in the distant prehistoric past. (The title is not a suggested rating for reviewers, but rather how many million years ago the story takes place.) So it is odd to contemplate that the Adam Driver character speaks Engish just so we can understand him, while his co-star speaks some other language. How different the story would have been if we understood her (Koa) and not him!
But I digress. So this turns into another Jurassic Park without the huge body count or those magic sighing moments of viewing a herd of docile grazing Brontosauruses or triceratops. Instead the dinosaurs start out as killing threats and remain so throughout. I suppose this is also a good reason to show the movie on a streaming service rather than on a large theater screen. That sort of access might have tilted the movie away from sci-if thriller and towards mere horror.
I had this weird and unrealized vision of them showing some sign of these alien visitors millions of years later along with other fossil remains, but perhaps fortunately perhaps, nothing like that developed.