Nick Redfern has a new Mysterious Universe article about surviving prehistoric animals. It's not your normal "plesiosaurs survived extinction" thing, though - its about ghosts! Redfern discusses some other researchers who have investigated things that look like pterosaurs, but they are said to be ghosts. He also goes into the Loch Ness Monster, but you can read the article to see that.
This is kind of getting into the "explaining something unexplained with something else that's unexplained" thing, and most researchers will probably not like that. I think it's pretty interesting, though.