Yes, mammals flourished during those times. The climate changes as it always does. https://www.oregonencyclopedia.org/articles/john-day-fossil-beds-fauna-and-climate-change/
The fact that CO2 levels were considerably higher and that all species thrived says a lot.
I'd say you're the one with the uneducated opinion, at least I travel and see with my own eyes rather than just staring at a computer all day and thumping out BS on Hot Copper.
Leftie climate change idiots who think that driving an EV will bring down the temperature need their brains overhauled.
