Of course I of all people have dinosaurs. Not even dinsoaurs, all sorts of extinct weirdos. They just, turn up in appropriate places, generally not jungles. The "What if I just, stuck the Western Interior Seaway back in the middle of North America" continent has a lot of 'em, but they can be found in other places. Canonical explanation? The world is near the bottom of various universe so dinosaurs and other things slipped through minor breaks in reality, creating a messy world that has anything I require at a time. Every time some crazy magic thing happens in another realm, that's a chance for something else to drop down in this one. The rare enviroment in my ridiculous land is the scale tree swamps, of "Here's some 100 foot tall 'trees' that are grouped way too close together in a swamp, let off spores at one time, and then die en-mass" very much extinct fame
Dinosaurs are feathered if appropriate, which is typically yes on maniraptorans, maybe on tyrannosaurs (See: Yutyrannus or Nanuqsaurus for the dino equivilent of polar bears), and quills on a few misc ones in Ornithischians (generally heterodontosaurians if they show up, or more likely ceratopsians). Pterosaurs, however, are always fuzzy
One day I gotta plug away at numbers and actually whip up some stats for a Rhizodus to inflict on other people aside from 'reskin a crocodile, make it stay in the water'. Worried about dinosaurs? Don't be, I can pull up much worse. I got pterosaurs for the sky, rausuchians for the land, all sorts of wonderful fish, molluscs, eurypterids and lobopodians for the water