The St. George Dinosaur Discovery Site (2017)
by Thomas Farley / email@example.com
Representative writing — much more at https://southwestrockhounding.com
Sheldon Johnson wasn’t looking for dinosaur tracks, he was just trying to flatten a hill. What the eye doctor found, though, was certainly eye opening. That Utah hill is now the St. George Dinosaur Discovery Site at Johnson Farm. It is a world class locality preserving an entire Jurassic ecosystem. Say hello to the land of dinosaurs.
St. George is located in southwest Utah. It’s 119 miles from Las Vegas and 302 miles from Salt Lake City. People flock to St. George to visit nearby Zion National Park and Bryce. At Zion, cliffs of red and white Navajo sandstone dominate. At Bryce Canyon National Park, natural amphitheaters and distinctive geological features called hoodoos populate the area. Southwest Utah is a wonderland for geologists. And paleontologists.
The history of the St. George Discovery site begins in 1992. That’s when the city of St. George built a road extension through Dr. Johnson’s alfalfa farm. The finished road sat 25 to 30 feet lower than an adjoining hill. Sometime in 1998, Johnson began lowering the hill with heavy equipment. He wanted to eventually meet the grade of the road. Once done, his roadside property could be more easily developed. He was moving forward with this work when he hit layers of sandstone.
The overlapping plates of sandstone couldn’t be scooped up and dumped like loose dirt. Instead, he had to split up layers with his track hoe. For many months he sold the blocky pieces for landscaping use. One day a piece flipped upside down, revealing a large natural cast of a dinosaur foot. Dr. Johnson immediately contacted the correct authorities, including his stepson, Kelly Bringhurst, a geology professor at nearby Dixie State College.
Paleontologists and geologists converged on Dr. Johnson’s farm and all agreed he had made a major discovery. Trace fossils abounded on the hill and on land around his property. The site had to be preserved. Three years of private fundraising ensued. State and federal grants were sought. Finally, the Johnsons partnered with the City of St. George to protect the land and build the museum you see today.
In addition to preservation and education, continuing research is a vital part of the museum’s mission. Material from all over southern Utah comes in to be examined. Look for the museum’s lab at the back of the building. Behind sliding glass windows, volunteers and staff clean and otherwise work on fossils. Ask any guide if you have questions about what they are doing.
The Saint George Dinosaur Discovery site or SGDS is an invaluable resource for rockhounds, amateur geologists, dinosaur enthusiasts, and kids of all ages. It is a place to look, study, and in some cases touch dinosaur tracks and fossils. This opportunity is usually unavailable. Vertebrate collecting on public land is strictly prohibited. This means any fossil with a skeleton of cartilage or bone. Only scientists connected to paleontology get the necessary permits to collect vertebrates. At St. George you can see body fossils and trace fossils that are ordinarily off limits.
At SGDS you can see in an hour what might take a paleontologist a lifetime to discover. You can even touch certain fossils and casts. For example, one “handling table” allows you to hold several ancient treasures. (These fossils were not found at St. George but were brought there to further its educational mission.) The first is a back vertebra from an Ornithischian, a plant eating dinosaur. Next to it is a tail vertebra from a Sauropod. And next to that is another tail vertebra, this time from Hadrosaur, a duck billed dinosaur. Where else but places like SGDS can you hold in your hand a 200-million-year old piece of the past?
SGDS is famous for trace fossils. These are different from body fossils which are, as the name implies, parts of an ancient animal. Trace fossils point to behavior and activity. Running, squatting, and even tail dragging can be deduced from tracks and traces laid down nearly 200 million years ago. As Brian Switek put it in a book review on the subject, “Whispers in stone, trace fossils are moments of ancient life.” [‘Dinosaurs Without Bones’ by Anthony J. Martin. March 7, 2014.]
Trace fossils at SGDS consist of molds and casts. Molds are impressions. Casts are relief. To explain, let’s say you wanted to make a beaver footprint cast down by a creek. With some plaster of Paris, you would fill in a track that left an impression or mold in the soil. Once dry, you would pop out the hardened compound. You now have a cast. A mold can also form when a body fossil decays or dissolves, leaving an impression. So how did all these molds and casts come to be?
How impressions formed is easily described. An animal walked, ran, or dragged part of itself across soft earth or mud. In the case of SGDS, these tracks were usually left along the shore line of prehistoric Lake Dixie. A dropping lake level then helped in the process, allowing a hardening of the mud. These impressions would remain if not weathered out or otherwise destroyed over geologic time. What about casts? We noted how drying mud left hardened impressions. As the lake level rose again it brought sand with it, filling in those tracks. Layer after layer of sand which eventually became sandstone. When sandstone layers are split apart at SGDS they reveal both impressions and casts. A split sandstone block at the site shows both molds and casts and detailed signage explains the process.
The innumerable impressions at St. George are a challenge to paleontologists. Rarely can a track, a set of footprints, be positively linked to a certain dinosaur. Tracks are therefore given names themselves. At SGDS at least five track types have been tentatively identified. We’ll look at them now. Don’t be put off by the Greek and Latin to follow. Just remember that tracks have their names and dinosaurs have their names.
Eubrontes: Meaning “true thunder”, these are large tracks that have left impressive casts at SGDS. Some you can touch, in display boxes that are clearly marked. Eubrontes tracks may have been left by Dilophosaurus, a fish or small animal eating three toed dinosaur. Dilophosaurus was approximately 15 to 20 feet tall and 6 to 7 feet high at the hips. An outstanding Dilophosaurus life restoration is at the museum. The replica presents a not yet fully grown adult, bringing you face to face with a mouthful of frightening teeth.
Grallator: A much smaller theropod track than Eubrontes. Possibly made by Megapnosaurus, 3 feet high at the hips and 7 to 8 feet long. The restoration of it is a must see. Grallator impressions are the most common tracks at SGDS. A large free-standing trackway block shows 49 individual impressions, most of them Grallator. The block is against the far wall of the museum as you come in. To make clear, a trackway is a footprint pattern. It usually consists of many individual tracks, giving clues about how the animal moved or behaved. This massive sandstone piece at SGDS is the largest intact block of tracks in the world.
Granulator impressions below.
Anomoepus: Meaning “anomalous foot”, these are the rarest track at St. George. Studied opinions suggest they belong to a type of early plated dinosaur, Scutellosaurus. A fine, full sized life restoration of Scutellosaurus graces the museum floor. All the restorations or replicas at SGDS are done by skilled craftspeople, painstakingly creating a model of ancient life.
These tracks don’t belong to dinosaurs, but rather lizard-like creatures with the tongue twisting name of Sphenodontians. These plant eaters were quite common in the Jurassic Era but only one kind remains today, the Tuatara of New Zealand.
Batrachopus: Also non-dinosaurian, these tracks were probably made by a primitive crocodile-like animal called Protosuchus. It walked on four legs. Look for its restoration when you visit. Both Batrachopus and Exocampe tracks attest to the comprehensive look you get at St. George of Jurassic life – it wasn’t just about dinosaurs.
What else makes the site important? An indoor boardwalk takes you above the the prehistoric lakebed of Lake Dixie. Called The Lake Dixie Discovery Trail, you get to puzzle over the marks and impressions made by countless ancient creatures. This is a rare opportunity to view an original track surface. A recent addition to the museum, the trail allows you to get up close to the lakebed without damaging the surface. Tracks and other features are clearly noted.
(The photograph below shows the Discovery Walk before completion in April, 2016. It is now detailed and finished.)
Tired of looking down? Look up. Flying high is a restoration of Dimorphodon. It’s a pterosaur, a group often mistakenly called pterodactyls. These flying lizards might have been above Lake Dixie 200 million years ago. Pterosaurs represent the largest animals to have ever flown. But size isn’t everything in the the Jurassic. What about organisms with only one cell?
Stromatolites are often touted as the oldest fossils on earth. You may have seen them sold in rock shops or shows. They can date back billions of years. Stromatolites still exist today in places like Shark Bay, Australia and the Great Salt Lake in Utah. They are made up of cyanobacteria that grow up in layers, forming large mounds. SGDS has fossilized remains, as well as a living stromatolite from the Great Salt Lake. They may not be the prettiest things, but they represent a link to time before complex life existed on earth.
Since we’re at the tail end of this article, I should mention other tails. The museum has a rare cast of a dinosaur tail drag, that activity preserved forever in stone. There are also tail drag molds in different places at the museum. Be sure to look for them before you leave.
In closing, make sure to talk with the enthusiastic and knowledgeable volunteers. They made my trip. If you’re not sure what to ask, ask them what their favorite exhibit is. Or what they think the most important thing is to see at the site. Before you know it, you’ll have them engaging in warm and excited tones about all things dinosaur. Their passion is catching and you’ll come away eager to know more and to return again someday.
For Further Reading:
The Tale of The Tracks: A Guide’s Inside View of The Tracks at the St. George Discovery Site at Johnson Farm. Thomas R. Thompson (2009) TRT Productions
Tracks In Deep Time: The St. George Dinosaur Discovery Site at Johnson Farm. Jerald D. Harris and Andrew R.C. Milner (2015) University of Utah Press, Salt Lake City.
Both titles above are highly recommended and available at or through the SGDS gift shop: http://www.dinosite.org/ (external link)
Dinosaurs Without Bones: Dinosaur Lives Revealed By Their Trace Fossils. Anthony J. Martin. (2014) Pegasus Books. New York
Note: Dinosaur fossil excavation kits are available at Amazon and elsewhere. Although they do not contain real fossils, of course, they may be a good way to get kids involved before or after a trip.
Know if You Go
SGDS is family friendly. There’s a sandbox outside kids can play in to uncover hidden fossils. They can make tracks with track making sticks. A well done picnic area allows them a place to run around in if they get bored.
Ask about accommodations for dogs. They do not want any animal left outside in the hot parking lot and will work with you.
Picture taking is encouraged. The sometimes dim interior is challenging to photograph so be prepared. Flash photography is allowed. Low angle lighting helps bring out the relief of casts.
The store sells water and soft drinks and dinosaur related items including footprint replicas.
The museum is handicap accessible but most of the walkways have an up or down slope.
The parking lot in front is not exceptionally big. But there is RV and bus parking adjacent to the museum as well as on street parking. No charge.
Call for current admission prices. I paid $6.00 as an adult, children are lower.
St. George Dinosaur Discovery Site at Johnson Farm
(This information is supplied by them at their website)
2180 East Riverside Drive St. George, UT 84790
+1 (435) 574-DINO or +1 (435) 574-3466 — http://www.dinosite.org/
Summer hours (Mar.1-Sept. 30)
Mon – Sat 10:00 AM – 6:00 PM (Mountain Standard Time)
Sundays – 11:00 AM – 5:00 PM
Holidays: The museum is open for all summer holidays, including Memorial Day, July 4th, Pioneer Day (July 24th), and Labor Day
Winter hours (Oct 1-Feb. 28):
Mon – Sat 10:00 AM – 5:00 PM
Sundays – closed
Holidays: “The museum is closed on Thanksgiving Day, Christmas Day, and New Year’s Day. (We may close early the evening before these holidays as well as for special events.) Our museum is fully air conditioned, with water fountains, bathrooms, and a gift shop for your enjoyment. We also have an outdoor Dino Park play area for the kids!”