Stegosaurus in Carbon County

Jennifer Macy, Archaeologist, Billings Field Office
Photos by Jenny Alexander, Outdoor Rec Planner, Billings Field Office

Public lands in Carbon County, Montana, managed by the Billings Field Office are a popular destination for paleontologists looking to expand knowledge about dinosaurs in North America.

The Bighorn Basin Paleontological Institute (BBPI), headquartered at the New Jersey State Museum’s Bureau of Natural History, has held surface collection permits to work in Carbon County for nearly a decade. Near the end of the 2017 field season, a significant amount of “float” was observed while “prospecting.” Float is fossil material found loose on the surface rather than in its original place; prospecting is searching for visible clues to paleontological potential.

Although some of the fossils were weathered, others were well preserved, leading to minor excavations at the location. These excavations resulted in stegosaurus limb elements, including much of a “pes” (a foot, or rear paw) of a “tetrapod” (living and extinct four-limbed animals with backbones).

The pes was excavated, as was a fragment of an ulna (part of the forearm). Part of a femur was identified but not excavated at that time. The specimens date to the Jurassic Period, 150 million years ago. The number of visible bones indicates that the bone layer will continue to be productive into and even after the 2018 season.

BBPI will return to Carbon County in July to resume work on the stegosaurus site. Stay tuned for an update!