On Oct. 30, a paleontological paper describing a new mosasaur from South Dakota was released. Mosasaurs, aquatic reptiles that lived alongside the dinosaurs, were fierce predators of mesozoic oceans, and this new species is no different.
The new species, Jormungandr walhallaensis, is named after the norse sea serpent Jormungandr, also known as the world serpent, as it is said to encircle the earth beneath the sea. When the world serpent ceases to eat its own tail, Ragnarok, the Norse apocalypse, is said to begin.
While not nearly as fearsome or large as the Jormungandr of legend, this new mosasaur was still formidable. The creature was nearly 24 feet long, and had a shark-like tail that allowed it to swim rapidly through the late Cretaceous oceans about 80 million years ago.
“If you put flippers on a Komodo dragon and made it really big, that’s what it would have looked like,” said study co-author and Richard Gilder Graduate School PhD student Amelia Zietlow.
The creature was described in the Bulletin of the American Museum of Natural History, no. 464, in an article titled “Jormungandr walhallaensis : A New Mosasaurine (Squamata: Mosasauroidea) from the Pierre Shale Formation (Pembina Member: Middle Campanian) of North Dakota”.
First discovered in 2015, the holotype specimen consists of a nearly complete skull, as well as other miscellaneous elements such as ribs and vertebrae.
“After 200 years of scientific study, new mosasaur species are still being discovered as new localities are explored and specimens collected long ago are reevaluated using modern standards of species delimitation,” reads the paper describing Jormungandr walhallaensis.
