Plate tectonics, but iirc “pangea” was about 400 million years ago. But who knows what arrangement they were in 65 million years ago.
Glaciers and other frozen-over land masses from an ice age could mean that the dino actually walked a lot closer to where its fossil was found.
Lots of possible ideas I suppose, including a great flood or similar catastrophic event e.g. asteroid crashing into earth. Many ancient cultures repeat the story of the flood. But since 65 million years ago is a lot older than humans - possibly the fossil pre-existed the flood.
“But who knows what arrangement they were in 65 million years ago.”
http://www.revimage.org/map-of-the-earth-65-million-years-ago/
http://scotese.com/Default.htm