Down and dirty at a dig: A dinophile’s dream comes true
By Elena Victory (USA)
“You really should go on a dig” was the advice of a dear friend during the long, rainy winter of 2005. I was just gearing up to teach my annual, introductory paleontology class at a small college near my home outside Portland, Oregon. “Where?” I asked. “Who specialises in fanatics who read lots of dinosaur books and dream a lot, but has never dug up a real dinosaur?” She smiled and said, “I think Nate Murphy’s program would be good for you”.
It unfolded from there. I emailed Nate to find out availability. He emailed back, directly I might add. And so, I found myself outside of Billings, MT en route to my first real dig. It was a beautiful landscape: a few lonely Ponderosa pines stood like silent sentinels over a grassy landscape dotted with spurges, thistles and wormwoods. Through the eyes of a botanist, it didn’t look like dinosaur country to me.
That night, after a group of 35 excited diggers had made camp and their introductions, we were given a little history. The next day, we were going to dig our awls and shovels into the “Mighty Morrison”, a huge geological layer cake of shales and mudstones spanning several states and several thousand square miles. The Morrison graveyard also records a story of climate change. Early in the Jurassic period, Apatosaurus roamed on its home range encountering arid seasons part of the year and deluges the rest of the season (poor thing, I thought, just like Portland, Oregon). This area of Montana gradually became more humid, warm and stable in temperature – perfect for diverse plant growth, the grazing herbivores growing ever larger and the ultimate predators that preyed upon them.
Our group was equally diverse as Morrison megafauna – from 15 years old to over 70 – a pastor, teachers, students, high-tech professionals and retirees, and equal parts male and female. We were all different but all obsessed to some degree by the mystery of creatures living their lives 150mya at this very location. Later that evening, around the campfire and after a great dinner including a Stegosaurus chocolate cake, each person was asked his or her favorite dinosaur. Stegosaurus was the most popular, followed by Tyrannosaurus rex, Deinonychus, and Apatosaurus. One participant put it best:
I like Brachiosaurus because it is still the one sauropod that can hold its head up high”.
I retired early to the lingering sounds of laughter, coyote songs, the moans of cattle and twinkling stars. I could not wait for the next day!
Although tourists know Montana as “Big Sky Country”, its name means, “rock”. Our quarry looked like a jagged scar of rock on the northern edge of this formation. In the summer of 2005, this “rock” yielded a rare sauropod skull, neck vertebrae and isolated limb bones of a new species. Discovering more of these bones was our goal, but other professionals were looking for tiny microfossils (clams and snails), plants, and other animals once living among these leviathans. They too tell a story and would help to reconstruct the world in which dinosaurs lived, breathed and moved.
The early morning hours were spent hauling debris (called “overburden”) from the site. This is a tedious process and great for beginners. It is also a great cardio workout. Other beginners received an awl and a brush. I dutifully stuck my awl directly into the Morrison. When the matrix crumbled, I diligently brushed and brushed and brushed. Just like the birth of a child, all this pain of labor is forgotten in a split second when one finds a real bone or when one thinks it is a real bone.
Some novice diggers I noticed are by nature paleo-pessimists. They probably will never find a bone though they dig and brush very diligently. Some folks are paleo-optimists and think everything they find is a bone. They tend to brush less and talk more. Both situations are problematic for a paleontologist leading a group of new diggers. Being an optimist and because it was a sunny and very hot day, I believed I had found a beautiful toe bone. It certainly looked like it from pictures I had studied. Both optimists and pessimists regularly consulted with our fearless leader, Nate Murphy or his son, Matt. When I excitedly pointed out my “toe” bone to Nate, he merely smiled and asked me: “You sure about that?”
Later in the day, I asked Nate how the eyes of paleontologist discern dinosaur bone from the endless acres of brown sediments. He led me over the edge of a bluff and pointed a finger at fragments of bone glinting blue in the afternoon sun. At first, it looked like any other rock, but upon closer inspection, these bone fragments, called “float”, sparkle. They are porous too, because they are the fossil remnants of spongy bone cavities that once coursed with blood supplying oxygen to these huge animals. My toe bone was no bone at all, but a concretion, a calcium-based lump of rock that just happened to be shaped like something akin to a bone. Gulp. How embarrassing! However, I will never forget what I learned. And here is another trick: lick bone and it will stick to your tongue a bit. Lick rock, and well, it just tastes like dirt. (This is one thing you can try at home, just in case you optimists think you find dino bone in your backyards.)
By midweek, we had reached our hottest day. The graveyard I started with yielded nothing more than a rib bone. Though not much was happening for me, just over the hill, a new and exciting development was unfolding! Some of the team had found remnants of what looked stegosaurian. This group was digging a ‘T’-shaped trench with the long axis of the ‘T’ cutting into the hillside. A lot of excitement was going on here and later I would understand why.
The second-to-last day of the dig, I found my paleo-calling. I was pulled off the rookie graveyard and moved to a new site with harder shales. Deep ravines cut through these hillsides. Upon scouting a bit at lunchtime, my eye found loads of glittering dinosaur bone, fossil shells and even a turtle shell. (Wow, “I’m good,” I thought.) The group I worked with had power tools and was hunkered down over something BIG! This was more like it. This was paleontology in all its glory. The BIG thing was a BIG bone, a massive femur or thighbone of another sauropod. The sweet sound of a jackhammer was roughly carving out a cavity around the bone. Smaller air scribes powered by a gas generator were honing in closer to the bone. The goal was to carve around it so it stood on a “pedestal” of rock, raising it up in sharp relief to the surrounding matrix.
At first, I brushed while others handled the power tools. By that afternoon, when I was handed the air scribe, I found my heaven. With both vertical and horizontal strokes, bits of shale went flying. Others brushed and removed the debris. Little by little, more of this ancient treasure was revealed. Eventually, I learned this piece would be jacketed. That is, a band-aid of plaster and burlap would be wrapped around the bone and rock to stabilize it, much like a broken human bone. This would protect the treasured dinosaur leg for the winter so next season more of this same work would resume. The pedestal was important because next year this bone would be flipped over and plastered on the other side before it could go back to a lab for further study. I wanted to stay all night and scribe away, but I was coaxed to leave. Good thing too, for more excitement awaited us back at camp.
That evening’s camp was buzzing with the thrill of a new discovery – actually two discoveries. The first was hilarious and a lesson of what not to throw away. Someone had found a broken end of a femur, a much-needed missing piece, in a debris pile. (I think a paleo-pessimist threw it away last year.) Second, parts of a stegosaur were laid out on a table for display. Even a novice could recognize the triangular plates, vertebrae and tail spikes. One of the spikes had a hollow core with a crystalline geode formation inside. The excitement over this find was justified because one our British experts on the dig speculated that this was a new species and an older stegosaur than any in the fossil record thus far.
One last thing about getting down and dirty at a dig is worthy of mention. Most paleontologists are creative, multi-tasking individuals. Nate was no exception. Our camp had great amenities, like toilets with nice fragrances, warm showers, great food and music. Nate and his cameraman, Nick Mariana, demonstrated their musical talents with songs like “Overburden Blues” and “Dead Skunk in the Middle of the Road” that will stick in your head for a while whether you want them there or not.
What advice would I give the reader patient enough to make it to the end of this story? “You really should go on a dig”.
