The facts in the script about the wildlife at the South Pole are authentic. There are five species of albatrosses down there, twelve million penguins (whose main food source is plankton), etc. Likewise, there are many active and extinct volcanoes, with lava tubes and (presumably) underground caverns.
The lightning storm they witness inside the cavern is authentic as well, caused by static electricity built up from friction between rocks due to tremors and other disruptions.
There aren’t any bats in Antarctica, although they exist on all the other continents, including in Scandinavia. So if there were a suitable environment and food, such as in an underground cavern heated by a volcano’s geothermal energy, bats would be quite happy in Antarctica.
Snag Films did a wonderful documentary on Antarctica. (Free)
NOTE: The Carlsbad Caverns would be an ideal location for filming the underground cave sequences in the script. They’re only a few miles from the original HELSTAF at The U.S. Army White Sands Missile Range, an ideal set for the secret Nazi facility called Fatherland.