Time travel. Artwork of a pteranodon stealing a camera from a time traveller. The time machine in which the man travelled to this ancient Earth is seen at bottom right. A pteranodon was a type of pterosaur that lived on Earth during the Mesozoic era (around 245-66 million years ago). It possessed long, membranous wings and a bony crest on its head. Many scientists believe that time travel into the past is impossible because of the paradoxes it would cause. However, some solutions to Einstein's equations of space-time do appear to allow brief travel through time.