What does the presence of dinosaur footprints in an area where no dinosaur bones were found suggest?

Responses

Dinosaurs were never in that area.
Dinosaurs were never in that area.

The climate was too hot for dinosaurs.
The climate was too hot for dinosaurs.

The area was once underwater.
The area was once underwater.

Dinosaurs were at some time in the area.

Dinosaurs were at some time in the area.