[jpsb]

Many glacial advances and retreats have occurred during the last billion years of Earth history. These glaciations are not randomly distributed in time.Instead, they are concentrated into four time intervals. Large, important glaciations occurred during the late Proterozoic (between about800 and 600 million years ago), during the Pennsylvanian and Permian (between about 350 and 250 million years ago), and the late Neogene toQuaternary (the last 4 million years). Somewhat less extensive glaciations occurred during parts of the Ordovician and Silurian (between about 460 and 430 million years ago).

Dinosaurs were 225-65 million years ago.

[Torie]

Here is what Bryson wrote:

"No less intriguing are the known ranges of some late dinosaurs. The British geologist Stephen Drury notes that forests within 10 degrees latitude of the North Pole were home to great beasts, including Tyannosaurus rex. 'That is bizarre,' he writes, 'for such a high latitude is continually dark for three months of the year.' Moreover, there is now evidence that these high latitudes suffered severe winters. Oxygen isotope studies suggest that the climate around Fairbanks, Alaska, was about the same in the late Cretaceous period as it is now. So what was Tyrannosaurus doing there? Either it migrated seasonally over enormous distances or it spent much of the year in snowdrifts in the dark. In Australia - which at that time was more polar in its orientation - a retreat to warmer climes wasn't possible. How dinosaurs managed to survive in such conditions can only be guessed."

And there you have it.

[Torie]

I did blow it about the ice age though. I was just transfixed at how resilent T Rex was, in this case with cold. It was warm blooded, and a quite hyperactive and smart beast, folks think now, as I recall.