I think one of the biggest pet peaves for dinosaur people, is that a lot of people don’t realise that the Mesozoic (aka DINOSAUR era) was a three part series:
Part I: The Triassic (252-201 million years ago) was the first part with all the dinosaurs that no-one remembers the names of.
Part II: The Jurassic (201-145 mya) is when dinosaurs became dominant. This is when you’d find the Stegosaurus, Diplodocus, and Allosaurus.
Part III: The Cretaceous (145-66 mya) is the one you actually know a bit about. T-rex, Triceratops, Velociraptor (which was basically a chicken, FYI), Ankylosaurus, ended with a meteor impact in the Gulf of Mexico, etc.
Some people blame Jurassic Park for the common misconception, but damn it’s such a good movie… how can you be mad at it?