Under the pole star

"Arctic Dinosaurs" is a fascinating NOVA-PBS documentary about fossil finds of dinosaurs in northern Alaska, a region relatively close to the North Pole. Indeed, it was even closer during the so-called Age of the Reptiles. How could dinosaurs, large and supposedly cold-blooded, thrive under such conditions?

Painstaking research seems to suggest that the Alaskan climate during the Cretaceous wasn't Arctic, but temperate. It resembled that of the Alaskan panhandle. However, this still means that the winters were cold and forbidding. Add to this the "Arctic night". For various reasons, palaeontologists believe that the surprising diversity of dinosaur species found in the North Slope didn't migrate further south, but stayed put.

This opens up a lot of intriguing questions about dinosaur biology. Were they really cold-blooded, like crocodiles or lizards? Or were they actually warm-blooded? Birds, after all, are warm-blooded - and they descend from dinosaurs. Personally, I've always been fond of the idea that dinos were warm-blooded, furry and multi-coloured, so the idea of giraffe-like hadrosaurs living under the northern lights has an intrinsic appeal, LOL. (NOVA doesn't discuss their colour, though.)

"Arctic Dinosaurs" ends with the obvious follow-up question: if dinosaurs were warm-blooded (or something close to it), why didn't they survive the climate change after the asteroid impact at the end of the Cretaceous? The scientists interviewed on the show suggest that the climate had began to change for the worse already before the asteroid impact. Climate change was the favoured explanation for dinosaur extinction about 30 years ago, so it's interesting to see that theory stage a little come back. In a dramatic finish, the narrator suggests that perhaps the Alaskan dinosaurs might have been the last of their kind...

Definitively worth watching if you are interested in dinosaurs, or Alaska.