Nodosaur


Nodosaurs, or members of the family Nodosauridae, were armored, herbivorous (plant-eating) dinosaurs that lived from the Late Jurassic to Early Cretaceous periods (163 to 65 million years ago). Approximately five nodosaur specimens have been found in marine deposits in several areas of Alabama, all within the Black Belt. These animals lived at a time when a shallow ocean covered the southern half of Alabama and the northern half was likely dominated by closed-canopy forests.

This computer-generated rendering illustrates what an Alabama nodosaur Nodosaur Nodosaurs were quadrupedal (walked on four legs) and classified in the order Ornithischia, meaning they had "bird-like" hip structures; this order includes the well-known Stegosaurus and Triceratops. Nodosaurs are closely related to members of the family Ankylosauridae and both belong to the clade Ankylosauria. All members of the Ankylosauria are characterized by having short limbs, a flat and low skull, and bony armor (known as dermal osteoderms) that covered much of their skull and back. Nodosaurs differ from ankylosaurs in having a long, tapering tail rather than the ankylosaurs' club-like tail. Several types   of nodosaurs are also known to have premaxillary teeth (meaning teeth at the very front of their upper jaws), a trait that is absent in all known species of ankylosaurs. Although some members of the Ankylosauria are known to have grown as large as a mini-van, in Alabama, the nodosaurs tended to be smaller, ranging from 6 to 9 feet in length. The isolated nature of nodosaur finds suggests these egg-laying dinosaurs probably lived a largely solitary life.

Remains of nodosaurs have been discovered in numerous locations around the world, including Antarctica, Asia, Europe, and North America. In Alabama, nodosaur bones have been discovered in the Black Belt counties of Dallas, Greene, Hale, Lowndes, and Montgomery in Late Cretaceous marine formations that range from 83 to 65 million years old. These geologic strata include the Tombigbee Member of the Eutaw Formation, the Mooreville Chalk, and the Ripley Formation.

This nodosaur skeleton, on display at McWane Science Nodosaur SkeletonCurrently, there are 23 genera and 29 species that are recognized within the family Nodosauridae. Unfortunately, due to the limited preservation and rarity of nodosaur bones found in the state, Alabama nodosaurs cannot so far be assigned to any of the known taxa. However, much like other dinosaurs discovered in Alabama, such as Appalachiosaurus montgomeriensis and Lophorhothon atopis, nodosaur remains found in the state could represent a new genus and species. During the Late Cretaceous, what is now the central United States was covered by a large ocean known as the Western Interior Seaway. This seaway separated, for nearly 60 million years, the dinosaurs of eastern North America from those in the northern and western parts of the continent. This long period of isolation would have provided more than enough time for nodosaurs in Alabama to evolve characteristics distinct from those of all other known nodosaur species. More complete specimens will need to be discovered before any definite conclusions can be reached.

Nodosaurs were terrestrial (lived on land), but all of the recovered remains in Alabama (as well as those from the other dinosaurs in the state) have been discovered within marine deposits among shark teeth, sea turtle bones, and oysters. This odd occurrence is a result of these dinosaurs dying on the sea shore and being washed out to sea.

On display at the McWane Science Center in Nodosaur FossilsThe most complete nodosaur specimen known from Alabama was discovered in the 1960s in Lowndes County and is on display at the McWane Science Center in Birmingham, Jefferson County. Belonging to a very young individual, this specimen includes a partial cranium (with upper and lower teeth), limb material, vertebrae, and dermal osteoderms. These remains currently represent the second most complete nodosaur ever discovered east of the Mississippi River. The most complete skeleton, that of Propanoplosaurus marylandicus, was discovered in Maryland in 1997.

This nodosaur tooth was discovered just over the Nodosaur ToothThe first published account of a nodosaur from Alabama was written by paleontologist Wann Langston of the National Museum of Canada in 1960. He described a partial hipbone that was discovered by C. F. Barber, a field scientist for Chicago's Field Museum of Natural History,   in Dallas County in 1945. This isolated specimen can currently be found in the vertebrate paleontology collections at the Field Museum. Remains of other Alabama nodosaurs can be found in the collections at McWane Science Center in Birmingham and the Alabama Museum of Natural History in Tuscaloosa, Tuscaloosa County. Several nodosaur fossils discovered in nearby Mississippi are currently housed at the Mississippi Museum of Natural Science in Jackson and the National Museum of Natural History in Washington, D.C.

Additional Resources  

Langston, Wann, Jr. The Dinosaurs. Vol. 4, The Vertebrate Fauna of the Selma Formation in Alabama. Chicago, Ill.: Chicago Museum of Natural History, 1960.

Cutchins, Judy, and Ginny Johnson. Dinosaurs of the South. Sarasota, Fla.: Pineapple Press, 2002.

Ebersole, Sandy M., and James. L. King. A Review of Non-Avian Dinosaurs from the Late Cretaceous of Alabama, Mississippi, Georgia, and Tennessee. Bulletin of the Alabama Museum of Natural History 28. Tuscaloosa, Ala.: Alabama Museum of Natural History, 2011.

Jun Ebersole
McWane Science Center


Published January 13, 2014
Last updated June 24, 2014