History of the Earth: September 21. Triassic Antarctica
There was zero need to hibernate.
Within the supercontinent of Pangaea during the Triassic, Antarctica was pretty close to the South Pole, if not quite on top of it. Much of Triassic Antarctica was within the Antarctic Circle, though, and some reliable paleolatitude measurements put parts of the continent as close to the pole as 75° S Latitude. But there were still no glaciers.
So you're glad you read it, right? The reason a critter might hibernate is cool temperatures and restricted food supply brought on by months of darkness, which is one of the points made in topic article here.
