Did you ask Oda himself this or are you making things up
I know there are two different words.
Do you want me to bring the Wikipedia articles?
I also know in conversation, No one has ever called Dinosaurs dragons. Whenever any characters look at dinosaurs they say "Kyuryu", which directly translates to dinosaur not dragon
So Oda chose to name the dinosaur fruits after something they aren't. And Oda knows they aren't because when people look at the punk hazard dragon, they say dragon, "ryu". Not dinosaur.