How did the land look 100 million years ago?

Well first you have to understand that there were many time spans throughout the existence of Earth. She has changed dramatically; from deserts to tropics to ice ages. There is no real basis for scenery in prehistoric times other than it was changing quite rapidly. Shallows seas shrunk to grassy plains, tropical forests reduced to deserts, and mountains grew high. But if you're wondering what life was like for the most part in prehistoric times was that it was warmer than now and more of what most places like the tropics today would look like. Places like Canada and the United States long ago were much much warmer and looked more tropic. For a while the United States and Canada was split from east to west due to a shallow sea that covered most of eastern North America. For a long time, these tropics changed alot, due to ice ages forming throughout different time periods. So really the bottom line is that the world was much MUCH more warm and tropical. It was probably like spending a day in the Caribbean millions of years ago in Canada and the United States. Being in a tropical jungle with the warm air above. Nice! But also keep in mind that there were alot of creatures unfamiliar to most modern people that were probably dangerous....plants too that would probably look beautiful to the naked eye but dangerous up close.