The Moon was closer to Earth and the planet spun faster. Each day was a couple hours shorter and there were about 385 days in a year. It was warmer and the changing of the seasons was, in some places, barely noticeable. The oceans were also warmer and hurricanes were more common. The magnetic poles constantly changed. If you went back in time, depending which time you chose, your north-pointing compass would have pointed east, west or south.
For a large amount of time, there were no broad-leafed trees or flower-bearing plants. This was all within the last couple hundred million years. Earth has been around for over 4 billion years.
Perspective. Wild stuff.