Complex sentence: He drew a map of the path of the poles over the past 300 million years and stated that changes happen in the interval of 5 million years (minimum) to 30 million years (maximum).
Split into simpler sentences: He drew a map of the path of the poles over the past 300 million years. He stated the changes happen in the interval of 5 millions of years (minimum) to 30 millions of years (maximum).