[dogma1138]

The polar regions used to be warm rainforests up-to as recently as about 50m years ago.

The temperature of the oceans during the Cretaceous was 35c.

Finding dinosaurs in Antarctica or Lapland doesn’t mean anything really since those areas used to be quite warmer than most tropical regions we have today.

[ComputerGuru]

The article claims that the areas where fossils were found had winters with temperatures just above freezing, and that some evidence (fossilized young, growth patterns in bones, etc) indicates that the species lived there year-round rather than only migrating there during the warmer months.