A Dinosaur Hunt in the Hell Creek Formation with Paleoadventures!
A short video overview of the Dinosaur Fossil Hunt
Last year at a Geological Society of America meeting, I met Walter Stein. Walter is the paleontologist that runs Paleoadventures Dinosaur Digs. Later that week, I went on a fossil excursion with him and a few other fossil friends. This year I had the opportunity to fly to South Dakota to go to his dig site in the Hell Creek Formation.
The Hell Creek Formation
Image showing the KT boundary. The Hell Creek is Cretaceous, while the Fort Union Group is Paleogene.
The Hell Creek Formation is one of the most famous dinosaur bearing formations in the world.
It's the best sampled upper most cretaceous vertebrate assemblage in the world (Pearson et al., 2002) and,
more importantly, it has been extensively studied for over 100 years.
The KT boundary occurs near the contact between the Hell Creek formation and the overlaying Fort Union Group.
This is the famous boundary that marks the extinction of Dinosaurs.
The Hell Creek Formation is exposed in Wyoming, Montana, North Dakota, and South Dakota. It runs for roughly 700 km from east to west (Kirk 2002). The thickness varies throughout the formation, but is generally the thickest in the west at about 100 m, and thins toward the east to about 50-60 m (Murphy et al, 1995). The eastern most part of the Hell Creek contains intermittent marine beds. These marine beds mark the shore of the Western Interior Seaway at the very end of the Cretaceous. Similar formations include the Lance formation in Wyoming and the Frenchman and Scollard Formations in Canada.
Tooth Draw Quarry - A Lag Deposit
Walter Stein of Paleoadventures heading into 'Tooth Draw Quarry'
Amy and I spent three days of our South Dakota trip in 'Tooth Draw Quarry,' one of the many quarries Walter has found. The Tooth Draw Quarry is a typical lag deposit, or preserved river bed, in the Hell Creek Formation. It contains layers of gravel and sand that washed downstream in river and flood channels before being buried and preserved 65 million years ago. Isolated remains of dinosaur bones and teeth that have tumbled down the rivers can also be found intermixed within the preserved gravel beds. Turtle and crocodile material are also a very common find. Under rare circumstances associated remains can be found.
Digging in the Hell Creek Formation for Dinosaur Fossils
Since the Hell Creek is mostly sand and gravel with some intermixed clays, it's rather easy to dig. The only tools required are a scalpel, screwdriver, paintbrush, and glue. Sometimes a small shovel is needed to remove clay. If one uses larger tools, one risks damaging the fragile dinosaur fossils.
During the three days, we carefully excavated a section on the quarry wall. Every now and then, we would hit bone and slow down. Most of the time it was just bone fragments, but sometimes it would be a larger bone or tooth.
Some of the finds were scientifically valuable, so they stayed with Walter for research purposes. These finds included an Ankylosaur scute and an Acheroraptor tooth.
We took home some of the less scientifically valuable fossils. Among the many finds included the jaw section and possible scapula piece of an Edmontosaurus, part of a Triceratops femur, a Nanotyrannus tooth, and a few Triceratops teeth.
It was a wonderful experience spending time digging in such a famous formation that produces so many outstanding dinosaurs, including the type specimen of T. rex. I can't wait to go back!
Below are some images from the dig and some of the fossils found.
Johnson, Kirk R. Nichols , Douglas J., Hartman, Joseph H. 2002. "Hell Creek Formation: A 2001 synthesis", The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An Integrated continental record of the end of the Cretaceous, Joseph H. Hartman, Kirk R. Johnson, Douglas J. Nichols
Murphy, E.C., Nichols, D.J., Hoganson, J.W., and Forsman, N.F. 1995, The Cretaceous/Tertiary boundary in south-central North Dakota: North Dakota Geological Survey Report of Investigations 98, 74 p
Pearson, Dean A., Schaefer, Terry, Johnson, Kirk R., Nichols, Douglas J. Hunter, John P. 2002. "Vertebrate biostratigraphy of the Hell Creek formation in southwestern North Dakota and northwestern South Dakota." The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An Integrated continental record of the end of the Cretaceous, Joseph H. Hartman, Kirk R. Johnson, Douglas J. Nichols
Below are pictures and fossils from the dinosaur fossil hunt:
This image has a Triceratops Femur section and Frill fragment near the bottom left and an Edmontosaurus bone piece near the top left of the image.