Jurassic Campaign World
The inclusion of dinosaurs is a weird little element in many D&D worlds. And not just because you have to justify creatures using Latin names in a world without ancient Rome.
It turns out dinosaurs died out a really, really, really long time ago. Dinosaurs lived in our world 65 million years ago. Or, put another way, 64,985, 000 years before humans existed.
Humans have been around for roughly 500 generations. Give or take. Elves live 15 times longer than humans; if elves had been around a comparable number of generations to humans, they’d still only have been around for under a quarter of a million years. To be precise: 64,775,000 years after dinosaurs. It’s really odd to think that dinosaurs could be around, let alone unchanged, in a world for a length of time 285 times as long as theoretical elven history.
Gods can help handwave this. Since a world created by fantastic deities can have existed for a far shorter length of time than our world, helping justify why dinos haven’t either died out or completely changed… to say nothing of why dinosaurs that existed tens of millions of years apart – such as the stegosaurus and tyrannosaurus rex – can coexist. It’s maaaaa-agic