From discovery to display: how does a fossil go from the ground to a museum?
The dinosaur bones Liz Johnson and her team have found in western Moffat County are millions, maybe tens of millions of years old.
It’s not going to take quite that long to be ready to introduce a dino-hungry public to the find — one Johnson believes could be on the scale of the quarry on the Jensen, Utah, side of Dinosaur National Monument — but it is going to take a moment — or a decade — or two. There are more than a few steps yet to take before such an attraction can be accomplished.
These aren’t the first bones to be found in Moffat County. Johnson, curator of paleontology and science faculty at Colorado Northwestern Community College, said that there are several dig sites that have yielded fossils of other creatures, such as turtles, mammoths and other prehistoric animals.
On the day the large site was discoveredfound, Johnson said she and her team were helping the Bureau of Land Management plan resource management and sites of interest. A thunderstorm was well on its way to the region, meaning the teams had to hurry out of the area, due to its remote location.
The team found a small bone — roughly the size of a bead — prompting Johnson to take a closer look at what animal could have possibly left it behind. This, Johnson said, was when the larger discoveries were made.
“(I was taking) a look at this really cool little bone, and then I zoom out and I see all of these bones sticking out the hill — from big things to small things. I’m like, ‘Oh, hi,'” Johnson said. “People get zoomed in on things, and then when you bring it back, you’re like, ‘Holy crap.’ We had to get out of there quickly because of the thunderstorms, but this dig site has been known to us for a long time, and we haven’t really been able to go back with the manpower in order to look into it.”
Johnson said there are multiple large sites in the area, so it takes a lot of consideration to choose which sites get the most resources. That doesn’t mean it’s the only project or site receiving attention, but in the case of the most recent discovery, it’s going to take a lot of resources and time — most likely decades. In an area that could become a tourist attraction like the Jensen side of Dinosaur National Monument, that means Johnson and her team are going to have to spend a lot of time looking into what exactly is in the ground out there.
“We have bones on one side of the hill and bones on the other side of the hill. The odds that this is a huge football field worth of bones existing is pretty high, but I could be wrong,” she said.
Unlike popular depictions of paleontology — such as the “Jurassic Park” film franchise — digging up fossils and large bones is easier said than done. There are no X-rays that can see exactly what’s in the ground, and it can take months to break enough ground to even get to the stage where paleontologists can use small brushes and other tools that are often seen in pop culture depictions of the science.
The entire process, known as field work, begins with what Johnson calls “prospecting.” Similar to prospecting for gold or other minerals, it takes a lot of walking around areas with good “outcrop,” or visible land with few trees and shrubs.
“Bones are made up of lots of minerals — calcium (and) phosphate,” Johnson said. “Well, when you are in this middle-of-the-desert land, and you are this one sagebrush, you know, holding on, you’re saying, ‘I need minerals,’ because you don’t get it anywhere else. Their root systems go straight in the bone.”
If a hillside has just one bush, Johnson and her team can sometimes go to that bush and find a bone attached to its roots or nearby. That isn’t the only way to prospect, though. After the prospecting stage — which identifies a site — comes the legal stage. Depending on whether or not the bones were found on public lands or private property, that process can change. Once that part is complete, Johnson and her team begin removing the rocks above the bones.
“We don’t dig into the side of the hill. We dig from the top down, one, for safety, and two, it’s also going to be much better on the bones when extracted,” Johnson said. “You use pickaxes, you use jackhammers (or) you use rock saws — depending on how tough that particular rock is. Some of the types are soft, like mudstones, made up of old mud from river bottoms. Or if it’s made of compact, hard sandstone.”
This type of hard labor can be physically exhausting, and Johnson said she budgets 6,000 calories for men on her team and 4,000 for women.
“You start off in the morning and you keep going,” she said. “Whether that is on a cliff side, or it could be 20 feet deep or you could have to go 60 feet deep. It could be just a few little inches off the hill.”
After that process comes what many think of when they think of digs like these.
“Quarrying is the sexy thing that you see in ‘Jurassic Park,’ where everyone has brushes and pulls the bones. It magically appears,” Johnson said. “It’s not nearly as physically demanding, but it’s mentally demanding. You’re sitting on the same piece of rock, on angular jagged rock. Your butt hurts wherever you move, it hurts because it’s a lot of rock. It’s not fun, and you’re using chisels and hammers to remove rock until you find bone.”
Someone on the team finds bone, usually by hitting it, which leaves a finder mark on the bone itself. He or she then traces the outline of the bone, and, sometimes, that means running into another bone. That could then lead to the discovery of an entire pile of bones.
Once the bones are quarried, paleontologists move to the mapping stage, which involves collecting a massive amount of data. That data includes exact locations of where each bone was found and which bones were near each other, giving scientists a greater picture of what the area looked like hundreds of millions of years ago.
At this particular site, Johnson said, she has seen bones of large and small animals, meaning they probably lived in the same area at the same time.
Colorado used to be underwater and had reefs, like the Great Barrier Reef around it, Johnson said. Then it became a small mountain range where the dinosaurs lived next to the inland sea. There, hurricanes would come, and it was at sea level. When the Rocky Mountains were formed, this pushed fossils miles high, to where they are today.
“If you find bones, try not to move them,” she said. “Because once you move the bone, you lost the data, and it’s the data that matters.”
A lot of these bones can weigh upward of 1,000 pounds, or even as much as a few tons. With jacketing, the next step, the bones are plastered and covered in burlap to be transported. Due to the large size of some of these bones, it can be difficult to figure out how exactly to move them.
“Because all the bones are so compacted in there, we have to find natural gaps in where the bones are and work with how the bones are laying, so we don’t have to break bones,” Johnson said. “The bad news is that, you know, sometimes you have to break bones. The good news is glue. Glue exists for a reason.”
Johnson said the best-case scenario is having the least amount of gluing as possible. Finally comes extraction, or removing the bones, rock and jackets from the site. This takes a lot of cooperation and communication with BLM.
“If you have sites that are so scientifically important, everybody wants to see the data and everyone wants to see things get done,” Johnson said. “And so what’s nice is everybody’s working toward the same end goal, but extraction is hard. Sometimes you get to drag it out with a car. Or sometimes you have to do it manually.”
After extraction, bones are taken to the lab for preparation, which is more tedious work on each bone. Johnson said these hours build up quickly, and it’s possible for 400 man-hours of prep work to finish freeing a bone. Then, it goes to collections. Students in Johnson’s class make an exhibit for their capstone projects, and that exhibit is created so the public can see the bones.
“If we just keep it downstairs in our little basement, it doesn’t do the public good, because, remember, these are the public’s fossils,” Johnson said. “Everybody has an opportunity to see them. Even though we have tours and stuff at the repository, we want to make it even more accessible. We want to make it so people can come up and see these bones anytime they want versus coming down and having a tour whenever I’m available.”
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