Billy Meier In Jurassic Park
This guy claimed that he made friends with aliens, hopped on their space ship and travelled way back to the Jurassic era. He even claimed that he managed to take a snap while he was in the past. The image is hard to make out, but it does look like a pterodactyl flying above.
He later went on to explain exactly how time travel is possible, although it gets pretty deep! He said that this advanced race of extraterrestrials can manipulate a unit of time called a chronon so that they can travel both to the past and to the future!
John Titor's Futuristic Predictions
John Titor hit the headlines when he claimed to be a military time traveler who was reporting back from the year 2366. He made several vague predictions starting from events that were due to happen in 2004. There was quite a buzz surrounding him, however, many of the events failed to materialize which led to many believing this was some sort of elaborate hoax.
A special investigation even claimed that they found the people who made it were brothers from Florida. The legend lives on, and you can still visit their website for more information on the predictions.