Over 65 millions years ago the western United States looked completely different and was ruled by the King of the Tyrant Lizards, Tyrannosaurus Rex. Fast forward to present day and the Black Hills Institute of Geological Research in Hill City is one of the nation’s top T. rex research centers. Currently home to one full T. rex fossil, “Stan”, and an additional full cast, “MOR555”, the Museum has more fossils per square centimeter than any other museum in the world.
Founded in 1978, The Black Hills Institute specializes in mostly local fossils, including Western South Dakota, Northwest Nebraska, Southeastern Montana, and Western Wyoming. Much of that region has exposed rocks of Late Cretaceous age including outcrops of the terrestrial Hell Creek and Lance Formations, where T. rex is found, and outcrops of the Pierre shale – remnants of a seaway. Despite popular opinion, T. rex is a product of the Cretaceous Period and not the Jurassic.
The Institute has sold fossils and casts all over the world and has well over 50 full-creature fossils they can produce casts of. While I was visiting, they were working on a replica of “Stan” the T. rex that was destined for someone’s house. To do this, they have to carefully prepare the original fossil and make a mold of it with silicon rubber. This is usually reinforced with fiberglass or a dense foam. Then they mix a very durable foam to pour inside the mold. After some detailed trimming with a Dremel tool the casts are ready to mount. Once completed, it will take a crew nearly one hour to fully erect “Stan.”
Back in the Museum, you will be overwhelmed with the concentration of high quality exhibits ranging all throughout prehistory. They have a large and very beautiful collection of Ammonites, which are an extinct group of marine mollusk. There is an extraordinary meteorite exhibit that has both local modern meteorites as well as one from Lake Murray, OK, that landed during the Cretaceous Period. And of course, “Stan” is always on view. Scientifically known as BHI 3033, “Stan” is one of the most complete T. rex fossils with roughly 199 of 300 bones recovered from his skeleton. Measuring in at 11.8 meters or 38.7 feet, “Stan” is a very impressive creature to stand next to. Fun fact: Until recently, “Stan” was the only T. rex on display in the same state it was found.
I personally thought the skull of the extinct Deinosuchus was particularly impressive—the full creature is speculated to have measured up to 60 feet long. It lived about the same time as the T. rex and the while the fossils have never been found in the same place, they may well have encountered one another. During the Upper Cretaceous Period, a body of water known as the Western Interior Seaway completely covered central parts of North America and measured 600 miles at its widest. While the T. rex has only been found on the Western side of the Interior Seaway, Deinosuchus has been found on both sides and primarily in Georgia and Texas.
The event that killed the dinosaurs—is known as the K-Pg event and it occurred approximately 66 million years ago. A massive comet or asteroid measuring over six miles wide impacted in the current day Gulf of Mexico launching rock and debris into the sky, creating a cloud that would inhibit sunlight for up to a year. All around the world, the geological record shows a layer of clay containing up to 1000 times the Iridium of the upper and lower layers at the time of impact. While Iridium is rare in Earth’s crust, it is abundant in asteroids. Keep an eye out for a new exhibit at the Museum focused on the K-Pg event that will hopefully happen sometime this summer.
Before you leave, make sure to stop at Everything Prehistoric where you can buy real fossils, minerals, agates, or any of a wide variety of geological treasures. They also carry jewelry, toys, books carvings, DVDs, and many other great gift items. If you really love paleontology, you can also inquire about full fossils that for sale (at the time of this writing they had a full juvenile Allosaurus skeleton for sale, but I’m sure it won’t be there for long). If you’d like to learn more about the history of the Black Hills Institute, be sure to check out the Dinosaur 13 documentary, currently available on Netflix.