Researchers from the American Museum of Natural History have made an exciting discovery in North Dakota, as they unearthed a new species of mosasaur that they believe could fill the evolutionary gap between two iconic ancient creatures. Dubbed Jormungandr walhallaensis, this 24-foot-long aquatic lizard inhabited the Western Interior Seaway during the late Cretaceous period, approximately 80 million years ago. The findings were recently published by the American Museum of Natural History.

The name "Jormungandr" was inspired by Norse mythology, referring to a mythical giant serpent and the offspring of Loki. The choice of the name Jormungandr was influenced by the reptile's findspot, near Walhalla, North Dakota, correlating with Valhalla, the Norse warrior afterlife.

Lead author Amelia Zietlow, a biologist at the Richard Gilder Graduate School at the American Museum of Natural History, described Jormungandr as resembling a "Komodo dragon with flippers, but much larger." The specimen includes a nearly complete skull, seven cervical vertebrae, several dorsal vertebrae, 11 ribs, and additional yet-to-be-identified post-cranial elements.

Based on the presence of a layer of bentonite beneath the bones, the researchers determined that Jormungandr lived during the late Cretaceous period, about 80 million years ago, predating the extinction of the dinosaurs. The team believes that Jormungandr shares characteristics with Clidastes, a smaller mosasaur species found farther south in the Western Interior Seaway, and Mosasaurus, a gigantic 50-foot-long mosasaur that coexisted with the Tyrannosaurus rex.

Paleontologist Clint Boyd from the North Dakota Geological Survey emphasized the importance of understanding the geographic and temporal timeline of this fossil, stating that it contributes to our knowledge of a poorly understood period in U.S. history.

Mosasaurs, marine reptiles that thrived during the Cretaceous period, were a diverse group of predators. These creatures are still being studied intensively, with researchers constantly making new discoveries concerning their intriguing features. Recent studies revealed evidence of mosasaur egg-laying, their ability to widely open their jaws, and their potential for venomous bites. Additionally, another mosasaur species was described earlier this year, featuring uniquely ridged teeth.

The discovery of Jormungandr adds an important piece to the puzzle of mosasaur evolution. By expanding their knowledge of the family tree, researchers hope to better understand the relationships between different forms of these ancient marine reptiles. The study of mosasaurs continues to surprise, with scientists excitedly anticipating future finds that will provide greater clarity on these fascinating creatures.

As our understanding of mosasaurs evolves, it seems that mosasaurs may become even more formidable and awe-inspiring than previously imagined.