Dino-Newt

One of the rules of evolution is that organisms tend to evolve to fill any open ecological niches. In the early Triassic period, the role of "big, dangerous land animal that eats anything that moves" hadn't yet been filled by the carnivorous dinosaurs, so it's not surprising to learn that a huge amphibian stepped into the breach.

According to a new paper in the Journal of Vertebrate Paleontology, an ancient amphibian called Kryostega roamed Antarctica 240 million years ago. Kryostega looked more like a crocodile than a salamander--it was 15 feet long, with a long, narrow head studded with huge upper and lower teeth.

If you're wondering how any creature--much less an oversized amphibian--could make a living in prehistoric Antarctica, bear in mind that the southern continent used to be much more temperate than it is today, hosting a thriving ecosystem. It's a safe bet that at least some of earliest dinosaurs (which evolved about 230 million years ago) also lived way down under, after Kryostega had gone extinct.