Johmarr
On our planet Earth, the non-avian dinosaurs died out during the Cretaceous-Paleogene extinction event. On another world, a few steps away from this reality, the comet that triggered that event didn't hit the planet. Other forces came and went, but non-avian dinosaurs survived, flourished, and evolved into a sentient species: the Johmarrik. They call their world Johmarr. And through various means, some of them--us--have found our way here.