.51" Fossil Nodosaur Tooth in Rock - Judith River Formation

Nodosaurs are a family of ankylosaurian dinosaurs that lived from the Late Jurassic to Late Cretaceous periods. They were medium to large-sized, quadrupedal herbivores that were heavily armored, adorned with rows of bony armor nodules and spines. Unlike ankylosaurs, nodosaurs lacked mace-like tail clubs. Nodosaurs possessed small, leaf-shaped teeth, which can be impossible to distinguish from ankylosaur teeth when heavily worn or weathered. Nodosaur teeth have a characteristic "shelf" visible below a pocket in the crown, and no center ridge.

The Judith River Formation is one of the world's most prolific sources of Late Cretaceous vertebrate fossils. At least sixteen Orders containing more than forty Genera are known from the formation. These include fish, amphibians, mammals, and insects in addition to reptiles and avian (birds) and non-avian dinosaurs. Among the more interesting specimens is Leonardo, a mummified and fossilized Brachylophosaurus. This is a hadrosaur, a duck-billed dinosaur found with amazing soft-tissue preservation: skin impressions can be found on 90 percent of its body! The pattern in the skin on its feet is even preserved. In addition to Leonardo, the Judith River Formation contains the remains of the theropod Hesperornis, the only known freshwater Hespernorthid, a penguin-like bird.