New reptile species unearthed in North Dakota

NORTH DAKOTA: Paleontologists in North Dakota have made a remarkable discovery – a new species of mosasaur, the giant aquatic lizards that roamed the seas around 80 million years ago during the late Cretaceous period.

According to Popsci, the newfound species has been named “Jormungandr walhallaensis” after the Norse sea serpent, Jörmungandr, and the location in North Dakota where its fossils were found. Their findings have been detailed in a study published on October 30 in the Bulletin of the American Museum of Natural History.

According to Amelia Zietlow, a study co-author and PhD student at the Richard Gilder Graduate School, the newly uncovered mosasaur resembled a giant Komodo dragon with flippers. “If you put flippers on a Komodo dragon and made it really big, that’s what it would have looked like,” she explained.

The existence of mosasaurs has been known for over 200 years, with the term “mosasaur” predating the word “dinosaur” by approximately two decades. Nevertheless, numerous questions remain about these ancient marine reptiles, including how many times they independently evolved flippers and when they became fully aquatic.

Scientists believe that mosasaurs may have evolved their distinctive flippers at least three times, possibly even more. Additionally, there is still uncertainty about their closest living relatives, whether it’s monitor lizards, snakes, or an entirely different creature. The new specimen helps shed light on the evolutionary relationships among different mosasaur groups.

However, the fossil of Jormungandr was initially discovered in northeastern North Dakota back in 2015. The fossil included a nearly complete skull, jaws, cervical spine, and multiple vertebrae. In-depth analysis indicated that this fossil represents a new species, sharing features with two other mosasaur species: Clidastes and Mosasaurus. Clidastes was a smaller creature, measuring between six to 13 feet long, and lived around 145 million years ago.

Mosasaurus, on the other hand, was a much larger species, nearly 50 feet in length, and coexisted with the Tyrannosaurus rex between 99.6 and 66 million years ago.

The newly discovered mosasaur species, Jormungandr, measured about 24 feet in length and featured flippers, as well as a shark-like tail, similar to other early mosasaur species. It is believed to have had a bony ridge on its skull, which would give it “angry eyebrows.” Its tail was slightly stumpy, and shorter compared to the rest of its body. This fossil is considered a precursor to the larger Mosasaurus.

Clint Boyd, a co-author of the study and a paleontologist from the North Dakota Geological Survey, remarked, “This fossil is coming from a geologic time in the United States that we don’t really understand. The more we can fill in the geographic and temporal timeline, the better we can understand these creatures.”