Well, this study says the mean surface temperature of the Earth 100 million years ago as perhaps as much as 20degC higher than today:
Just a moment...
And this study shows the changes in the continents over the last 100 million years, starting with a grouping that appears not to have significantly less land area than today:
Most detailed geological model reveals Earth’s past 100 million years - The University of Sydney
Cordially,
Doc Honour