i think it's the sceintific consensus that most dinos were fethered at a stage of their life. ie i think trexes were only feathered as cubs. i dont think big tropical dinos like diplodocuses were feathered. most smalls ones? no problem. i have a nice vid about polar dinos i can show you. https://www.youtube.com/watch?v=5Ier8c9WFzE

also, many sinapsids (mammal like reptiles) might have had fur. https://i.imgur.com/SctG41N.png https://i.imgur.com/Se79CLz.png

btw, check out julio lacerda! my favourite paleoartist.