Leptomeryx |
Deposits across the continent show a sudden change in the climate at around the dawn of the Oligocene. By 'sudden' in this context, we mean over the course of hundreds of thousands of years, so it's hardly something you would have noticed had you been there at the time, but it's still rapid as such things go. The exact nature of the changes, and the speed at which they appear to have happened, depend on which part of the continent we're talking about, but nowhere was unaffected.