BILLINGS — It’s not often that a welder gets called out on a job like the one Andy Brekke recently undertook.
Brekke, owner of Beartooth Ironworks in Billings, drove to a ranch in the Grass Range area last week to build a frame to support two sections of odd-shaped rock weighing about 3,500 to 5,000 pounds each so they could be transported intact back to Billings. These weren’t just any rocks, however.
“It’s the first time anyone has called me to do a dinosaur,” Brekke said.
The two rocks encased in burlap, plaster and caged in Brekke’s welded steel frames are parts of the pelvis, torso and neck bones of a 150-million-year-old sauropod. Sauropods were a plant-eating dinosaur with a long neck and tail, a small head and four stout legs that roamed central Montana during the Jurassic period. This particular dinosaur could have been 55 to 60 feet long, over 18 feet tall and weighed around 10 tons. A full-grown male African elephant weighs about 6 tons.
“I usually take them out in the most manageable package, some guys will break stuff” just to make it easier to move, said Nate Murphy, paleontologist and founder of the Judith River Dinosaur Institute, whose crew uncovered the fossils.
But this time he decided to bring the fossils out in such large pieces so he could more closely control their excavation in his lab. That enables him to analyze rock around the fossils to test for bacteria, to understand how the dinosaur decomposed, and possibly pollen, to tell scientists more about the flora of the era.
“It’s kind of like the opportunity for a coroner to get a whole body rather than parts or pieces,” Murphy said. “This is the least invasive way to remove a dinosaur. I don’t do it a lot.”
The large slabs were also necessary because the bones were so intertwined that finding a place to split them apart was difficult.
“Believe it or not, that’s the smallest we could get it,” Murphy said.
It took three years to excavate the fossils, and early indications are that it could be a new species, although closely related to sauropods like camarasaurus and brachiosaurus.
After carting the large bones out of the backcountry in a trailer, across narrow trails and gravel roads, it was up to Brekke on Monday to weld wheels onto the frames he made and flip the rocks over to allow Murphy and his crew to take off a portion of the plaster cast and begin chiseling away to reveal the sauropod bones.
“I want to get to the top of the backbone right away because that’s the best diagnostic way to tell what it was,” Murphy said.
In the ground, the dinosaur was lying on its back, so once the rock is flipped and the fossil exposed Murphy will have a better understanding of what he’s uncovered. That could possibly be by December.
Most of the nation’s other sauropod bones have been uncovered south of Montana.
“A lot of scientists who have more experience in the Morrison (formation of rock) than I have say don’t be surprised if everything you find is new because it’s the farthest north,” Murphy said.
So what will Murphy be looking for to tell if this is a different species, or simply one of the same species although of a different sex or age?
“When you get to describe new species on a biological scale, scientists talk about features on bones, they change as they mature,” Murphy explained. “That’s why we have to look at the backbone. They fuse as they age.”
Just as exciting for Murphy are other sauropod bones he found at a nearby site, which his crew has nicknamed “the wrecking yard.” Although it’s still early in his investigation, based on what he’s seen of the sauropod’s vertebrae and ribs, it could be one of the biggest sauropods ever unearthed — possibly 125 feet long. The ribs alone are 8 feet long, so a cross-section of the animal’s gut would have measured 16 feet across. A full-sized pickup truck is about 19 feet long.
Both of the dinosaurs have come from the same ranch that Murphy and his crew have been working at for 12 years. So far the site has produced fossils from 10 dinosaurs — five of them stegosauruses — from what was likely a site of a massive flood that covered the animals in thick mud.
“It’s a Jurassic graveyard,” Murphy said.
Some of the bones are close to the surface, but for the big bones he’s unearthed the crew had dug back into the hillside 15 to 30 feet. The excavations have removed so much rock that the landowner was able to build a reservoir.
Cleaning off the large blocks of stone to reveal the bones will probably take two to three years of delicate hand work, Murphy said. The final cleaning is done using a sandblaster-type machine that instead uses dental-grade baking soda as the abrasive material.
“That’s when the bones really start talking to you, when they are cleaned,” said Mark Lent, who assisted Murphy in the recent fossil move and is active in the Billings Gem and Mineral Club. “That’s really cool because that will show you whether something has been chewing on it.”
Brekke used about 800 pounds of scrap steel — everything from channel and angle iron to pipe and rebar to create the unusual supports so the rocks wouldn’t break on the long drive to Billings. Then the crew used jacks, blocks and winches to slowly lift the large loads onto flatbed trailers.
“The hardest part is done, they got it here in one piece, two pieces I should say,” Brekke said.