Dinosaurs were only identified as a category of extinct animals in the 19th century. Yet people would surely have found them before that. Dragon myths occur in various countries far apart as Wales and China. They are also mentioned in the Bible as a metaphor for the devil [Daniel and Revelation]. Could the remains of dinosaurs have given rise to these legends?
It's quite likely that some dinosaurs lived for considerable periods after the flood and gave rise to legends of dragons. remember that 'dinosaur" was only coined in the 19th century and the word "dragon" would have been used prior to that.
This might account for some locations legends, but not all. I suggest this because there was a documentary on an island in the Med. that has fossils close to the surface.
There is always the possibility that what we learned in history is wrong and also that our dating systems are off. Meaning maybe humans and dinosaurs did co-exist.