Fossil Hotbed Uncovered in Missouri Confirms New Species of Duck-Billed Dinosaur

During the 1940s, the first dinosaurs found in Missouri were unearthed on accident while a family broke ground for a new well. Now, roughly 80 years later, more dinosaur fossils of the same species were uncovered and identified 50 feet from the initial fossil discovery, reports Sherry Liang for CNN.

After comparing the bones from the 1940s, others collected in the past eight decades, and the specimen recently unearthed in October, researchers had enough evidence to determine that the new fossils are officially part of the new genus and species, USA Today reports. The new bones included the skeleton of a juvenile and adult dinosaur belonging to a species of duck-billed dinosaur called Parrosaurus missourenisis. The remains were unearthed by researchers from Chicago's Field Museum and the Saine Genevieve Museum Learning Center, reports the Independent's Gino Spocchia.

The treasure trove of bones helps paleontologists learn more about the Western Interior Seaway, a shallow sea that divided North America in half over 70 million years ago. While most dinosaurs in the United States are excavated out west, this dig site—dubbed the Chronister site after the family whose property the fossils were found on—would have been located on the seaway's eastern shore millions of years ago, reports USA Today's Mike Snider.

"Most of the dinosaurs that every 6-year-old is familiar with, Tyrannosaurs, your various horned dinosaurs and duck-bills, and so on, were living west of the Seaway," Peter Makovicky, a paleontologist who was previously a curator at the Field Museum, tells USA Today. "From the eastern seaboard and the Midwestern states, we have far, far less knowledge of dinosaurs. So when you actually find a site where you have not just scraps, but multiple skeletons together, that's a real windfall."

Excavations that revealed the adult skeleton began in 2016 after Guy Darrough, a curator at the Sainte Genevieve Museum Learning Center in Missouri, contacted Makovicky after finding a juvenile dinosaur skeleton at the site, reports Meghan Roos for Newsweek. Upon traveling to Missouri and seeing the Chronister site, Makovicky had a dig team sent over, USA Today reports. After years of excavating, the team found a tail, two arms, and a skull belonging to a duck-billed dinosaur that would have been 35 feet long.

In October, the excavation team lifted the adult dinosaur's body, which is about the size of a Volkswagen weighing 2,000 pounds, from the ground using a crane. The specimen will be shipped off to the Field Museum in Chicago for preparation and further study, per CNN. The juvenile skeleton will be on display at the Sainte Genevieve Museum Learning Center. Visitors will get the chance to view paleontologists' work on the fossil in Sainte Genevieve beginning December 11, per Newsweek.

Before this new evidence came to light, bones from the Chronister site were misidentified for decades. When they were first discovered in the 1940s, Dan Stewart of the Missouri Geological Survey convinced the Chronister family to ship the bones to the Smithsonian National Museum of Natural History.

In 1945, Smithsonian paleontologists Charles Gilmore and Dan Stewart suspected the bones belonged to a sauropod, or a clade of long-necked dinosaurs, according to the Bollinger County Museum of Natural History. In the 1980s, Bruce Stinchcomb, a paleontology student studying Gilmore and Stewart's, analyzed the old bones and identified them as belonging to a hadrosaur, or duck-billed dinosaur, per CNN. Teeth found at the site provided enough evidence that the dinosaur was not a long-necked sauropod.

In ongoing digs, Makovicky and his team of paleontologists also found several turtle fossils in the area and other parts of four different dinosaur species, CNN reports. Makovicky suspects that the site will yield at least four duck-billed dinosaurs. 

"It's an unusual site. It seems to be a small, contained clay deposit, unlinked to other deposits around it," Makovicky tells the Kansas City Star's Mitchell Willetts.

Elizabeth Gamillo | | READ MORE

Elizabeth Gamillo is a correspondent for Smithsonian and a science journalist based in Milwaukee, Wisconsin. She has written for Science magazine as their 2018 AAAS Diverse Voices in Science Journalism Intern.