Evidence has been found to suggest that giant creatures such as the massive one-tonne titanoboa snake would have thrived in hot jungles millions of years ago with temperatures significantly warmer than those seen today.
"Fossil boffins say that dense triple-canopy rainforests, home among other things to gigantic one-tonne boa constrictors, flourished millions of years ago in temperatures 3-5°C warmer than those seen today - as hot as some of the more dire global-warming projections."