No easy task moving prehistoric reptile tracks to the Museum of Northern Arizona
by Sam McManis
Whatever prehistoric reptile it was that, epochs ago, made tracks in the muddy rock on the Molenkopi Formation almost certainly moved faster than the front loader chugging along Highway 180transporting this 240-million-year-old slab on Wednesday from a construction site where it was found to its permanent home at the Museum of Northern Arizona.
The actual 1.6-mile trip for this extraordinary artifact, believed to be from the early to middle Triassic Period, took only 10 minutes or so from the Starpoint Apartments construction site to the west entrance of MNA. Getting the hulking mass, a 5-ton hunk of reds and stone, to the courtyard at MNA proved an all-day exercise in engineering prowess and plain brute strength.
It seemed simple enough, the moving plan.
Once the front loader gently rested the rock on pallets at the museum’s west entrance — the doors had been temporarily removed — Joe Darger’s crew of nine men and a cattle dog named Carly would roll the thing on pallet jacks through the Sarah Lee Branigar Room, down a ramp to the left past the History of Clay exhibit, then make a sharp right at the Liberating Landscapes exhibit before rolling onward into the courtyard under an awning to its final resting place.
Piece of cake, right?
The going was slow, arduous and not without a few setbacks. While the crew from Straightline Builders — donating its time, equipment and muscle —adjusted heavy-duty ratchet tie down straps and placed the wheels of the pallet jacks just so, David Gillette was pacing like an expectant father.
Gillette is the paleontologist -- officially retired from MNA but still on call -- who will be studying these clear and deep impressions from a reptile that predates dinosaurs to determine exactly what type of creature it was. His best hypothesis, from first glance: Chirotheriumrex, whose tracks have been found elsewhere on the Colorado Plateau.
But before Gillette can roll up his scientific sleeves and take more than just a cursory gander — and before MNA patrons can have a look-see themselves — there was the matter of getting the slab of sandstone embedded in one piece without harming the tracks.
Two hours into the installment operation, the nine men who, inch by inch, with groans and grunts and a push and pull that might have been hernia-inducing in less strapping workers, were moving the thing had finally made the first left-hand turn. Now they were ready to send the rock, propped up on two pallets with wheeled pallet jacks on each side, down the ramp.
The men paused, hands resting on the rock, covered by a tarp on the sides and Styrofoam on top (where the tracks are). Darger smiled and in his twangy drawl, sighed deeply and looked to worker Spencer Phillip.
“We’re blaming all this on Spencer,” Darger said, joking.
“Yeah,” another worker piped up, “why’d he have to find this?”
Phillip, the heavy equipment operator who came upon the ancient tracks in November when breaking up rock about 20 feet deep in the rutilant site, just shrugged.
How the tracks were found
His fellow crew members might have been giving Phillip some good-natured grief on Wednesday, but Gillette and museum officials were thrilled with his find.
“One of the guys was hammering and it was laying on its side,” Phillip said, “and when the sunlight hit it showed the shadows and that’s when I noticed (the tracks). I told him to stop breaking up(rock) and told the foreman to come over. I was ready to take it home, to my lawn, since it was just sitting there.”
MNA, of course, had other plans for it once it became aware of the find. Darger first contacted Jeri Young Ben-Horin of the Arizona Geological Survey, because she had been charting some faults in the area and had worked with the construction company at sites.
“Although I am not a paleontologist, but a mere geologist, such a find is obviously rare,” Ben-Horin said. “To me, this find was a little gift to the community and could be used as a teaching tool or for research. I have worked on paleontological sites and have studied rocks from Earth's very distant past, and to me each new find can tell us something important about the history of this planet, reminding us that we are a smaller part of the story.”
Ben-Horin’s first call was to Gillette. Even from a first viewing, taking place where the rock spent the winter under a tarpat the construction site, Gillette knew the tracks were something special. He and the museum received permission from Brinshore Development, which owns the apartment complex, to gain possession of the slab.
The tracks are in near pristine shape, given that they were laid some 240 million years ago and embedded deep in the earth. T here are four distinct tracks on the surface, indented about an inch into the rock.
Gillette said there also might be faint impressions of another set of tracks heading in a slightly different direction, though he cautioned that he cannot make a determination until he examines the tracks thoroughly.
“There’s at least one stride in there -- the back and front foot and the rear-foot step to the next rear-foot step, ”Gillette said. “I think we have four tracks that belong to one individual that were part of a footfall sequence. I can’t even guarantee that until I’ve had more time to look at it. It could be we’re looking at footprints from two individuals.
These are large pre-dinosaur reptiles walking along the flood plain, probably. Mud cracks had formed and they were malleable, so when the reptiles came down they squished in the mud. They hardened and were nicely preserved.”
Gillette estimates that the reptile in question was similar in size to a wolf, weighing about 100 pounds, but noted that its prints were more pointed, “not stubby toes like a wolf’s.”
Gillette’s excitement was palpable, because similar tracks have been found on the Colorado Plateau but only in a few places, and it’s believed none this far south.
“Maybe this is the first time we’ve gotten tracks in the Moenkopi Formation in Flagstaff,” he said. “We had reptiles in the Colorado Plateau right after the great Permian extinction. It took a longtime, 20 or 30 million years, to recover from the great Permian extinction. And the reptiles that recovered and lived in the middle part of the Triassic(Period) and left these tracks in the Moenkopi Formation, these reptiles were the precursors to dinosaurs. They aren’t directly in the line of ancestry to dinosaurs, but they are close. They set the ecosystem that dinosaurs originated in and evolved in.
“We may be able to tell more about what this animal was doing, how big it was and what kind of locomotion details, like speed and breadth of the hips and so on. This really gives us a glimpse into the life that existed after the Great Permian extinction, which wiped out 95%of all life on Earth.”
Making the move
Before any scientific inquiry can be attempted, the slab had to be put in place in the museum courtyard without its delicate, slightly brittle, red sandstone breaking up.
The block is 1.2 meters wide, about 1.8 meters long and almost a meter thick. Part of the unwieldiness in the move and placement stemmed from the fact the rock is not a rectangle (more like a triangle) and is significantly heavier on one side.
After its road trip down Highway 180, the block hung suspended from the loader outside the museum’s west entrance for nearly an hour while workers figured out how to place it on the pallet to move it through the doors and on its way. Once that was accomplished, a second pallet was employed and two pallet jacks were put on each end.
Now came the brute force part of the move. All nine workers, like pallbearers, surrounded the slab and, depending on their positions, pushed or pulled. It was all rather low-tech, the workers counting, “one, two, three” and then putting their shoulders into it and groaning with impunity. Once beyond the threshold, one worker paused and cracked, “Well, no going back now.”
That first left-hand turn was negotiated fairly smoothly but halfway down the ramp, there was a tearing sound, then athud and the rock listed to the right.
“We busted a wheel off the jack,” Darger shouted, showing great restraint in not adding a profanity. “Let’s get some burgers (for lunch) and I’ll get a new jack.”
Back to work 90 minutes later, the workers needed only a half an hour to make the hairpin right-hand turn at the Liberating Landscapes exhibit and made it to the courtyard. It was a little tricky slaloming the rock around the structural poles holding up the roof awning. Finally, they placed the rock under an I-beam that Darger had built by Robert South and John Novolt for the final placement in the courtyard.
An hour later, with the liberal use of a chain hoist, pry bars and lots of straps, they took the protective tarp off, removed the Styrofoam up top and, voila, success. MNA’s facilities director Andy Bryan bumped fists with Darger, who smiled wryly and said, “Easy-peasy.”
Seth McKee, one of Bryan’s assistants, stood over the slab and said, deadpan, “We got it upside down. What the heck?”
Relieved chuckles all around.
“Now,” Gillette said,“we can do cartwheels.”