Courtesy of Missouri Secretary of State
Missouri State Dinosaud-Hadrosaur
The Hypsibema missouriensis was named the Missouri state dinosaur in 2004.
Our State Dino
During the late Cretaceous Period, about sixty to eighty million years ago, dinosaurs roamed parts of southeast Missouri. Fossils found in the state come from what is known as the Chronister site near Glen Allen in Bollinger County.
Dan Stewart of the Missouri Geological Survey first identified dinosaur fossils in 1942 in Bollinger County. He was studying clay deposits in the area when he learned the Chronister family had found some large bones while digging a well. Stewart recognized them to be dinosaur bones and was allowed to send the bones to paleontologist Charles Gilmore at the Smithsonian for identification. Gilmore affirmed Stewart’s identification of the fossils as dinosaur bones and co-authored a paper in the Journal of Paleontology with Stewart about the find in 1945. Gilmore died shortly afterward, and the bones were mostly forgotten. The Smithsonian eventually paid the Chronisters fifty dollars for them.
Geologist Bruce Stinchcomb purchased the property in the 1970s. He found more dinosaur bones with the assistance of other paleontologists, including teeth, which allowed the dinosaur remains to be correctly identified as belonging to a hadrosaur or duck-billed dinosaur. The name paleontologists have assigned to the Missouri dinosaur is Hypsibema missouriensis. These plant-eating dinosaurs walked on all fours, reached lengths of thirty-five feet, and probably equaled the weight of an elephant. The number and arrangement of their teeth allowed them to feed on tough, fibrous plants. Much of southeast Missouri south of the Ozarks was covered by an arm of the Gulf of Mexico during the late Cretaceous. Researchers have determined that the site where Missouri dinosaur fossils are found was likely a coastal plain then. Fossils of crocodiles, turtles, and fish have also been found at the site.
Excavation continued under the direction of Guy Darrough and Missouri Ozark Dinosaur Project Inc. The Bollinger County Museum of Natural History houses the material collected from the site; it also contains a laboratory for preparation and study of the material.
The board of directors for the Bollinger County Museum of Natural History suggested naming Hypsibema missouriensis the state dinosaur. Representative Rod Jetton sponsored the legislation, which was approved by the legislature and signed by Gov. Bob Holden July 9, 2004.