Did spacemen colonise the earth?

the long version

In an endeavor to cast new light on the origin of man, a diversity of UFO - related mysteries linked with historical personages and events are also outlined in this thesis. e.g. what were the three apparently inter-related factors associated with the rapid extinction of the dinosaurs about 65 million years ago? And what was the profound significance of the aerial object sighted over Cornwall about the end of the fifth century.