After a day of braving bad weather and hiking through knee-deep mud, Chilean scientists on one of the final days of their expedition to Antarctica discovered possibly the largest monster ever to swim its waters, according to a press release. What they found was a mosasaur skull approximately 4 feet long, Live Science reports. That would make this particular mosasaur—a giant sea lizard that lived during the end of the age of dinosaurs—more than 32 feet long. The Chilean paleontologists named the new species—only the second mosasaur ever discovered in Antarctica—Kaikaifilu hervei and published their findings this week in Cretaceous Research.
The fossilized Kaikaifilu skull was found in rocks that were 66 million years old. At that time, Antarctica was much warmer than it is now. That change in climate means it's a hard place for paleontologists to work, but it also means major discoveries are still possible. It's rare to find mosasaurs in the Southern Hemisphere, especially outside of New Zealand. The Kaikaifilu skull is only the second mososaur skull discovered in Antarctica. Thanks to its discovery, scientists now believe that various teeth found on the continent over the years all belong to Kaikaifilu and not multiple types of mososaurs as previously believed. (Researchers say ancient sea reptiles were dark as night.)