Plesiosaurs are some of the most easily recognisable animals in the fossil record. Simply uttering the words 'Loch Ness Monster' can conjure a reasonably accurate image of what they look like. Thanks to palaeoart, it's also fairly easy to envision how they lived: swimming through the open Jurassic seas, picking fish, ammonites and belemnites out of the water.

What we don't imagine are plesiosaurs at the South Pole, nor would we ever picture them swimming amongst icebergs or poking their heads out of holes in the ice to breathe. We'd never think to find them in freshwater either. Even more surprising is that the evidence for this radical vision of polar plesiosaurs is found preserved in the precious mineral opal.

In this interview, we're joined by Dr Benjamin Kear, Curator of Vertebrate Palaeontology at the Museum of Evolution, Uppsala University in Sweden. He paints for us a picture of life at the South Pole and the importance of polar habitats in driving the evolution of the plesiosaurs.