Pterosaurs also seem to have a fair bunch of sightings and witnesses.
Here are a few links, some creationist driven, which worries me, any third part with a hidden agenda (proving the young earth theory) makes them biased in the wrong direction IMO.
However, the eyewitness reports from teachers, police etc, and once again sightings by more than one person at a time. if this does exist I reckon it would explain away mothman, the Jersey Devil and maybe a few other oddities.
They have been allegedly sighted in Papua New Guinea, Africa (known as kongamato or 'overwhelmer of boats' there) America and here in good old Oz. Doubt we have one here, Steve Irwin would have caught it by now
Having said that, the only video I have ever seen of a ropen turned out to be a frigatebird. Still, one can hope, they are serching right now in Africa for other dino's...
Promised links
Siassi SightingPNG SightingsGenisis Park LinkCameroon ExpeditionProbably just a big bat. Worth a look anyways.