The Middletown Press (Middletown, CT)
SKELETON CREW
Dismantled Peabody brontosaurus to head for Canadian rehab
NEW HAVEN — Stegosaurus has headed for Canada. So has Archelon, the giant turtle.
Other fossils and mammals have been crated and sent to Yale University’s West Campus for storage.
In fact, other than Xiphactinus, the
mounted fish skeleton taken off the wall and sitting on the floor among crates and tools, all that’s left in the Great Hall of the Yale Peabody Museum of Natural History is Brontosaurus.
And it will be headed for Trenton, Ontario, as early as this week, where Research Casting International will clean and repair each piece of the giant fossil, removing the old plaster that held it together for almost 90 years.
Brontosaurus will return in time for the Peabody’s reopening in 2023 (the Great Hall closed Dec. 31 but the rest of the museum remains open until June 30). Then, the dinosaur will look less like the lumbering “thunder lizard” envisioned by O.C. Marsh, Yale’s original paleontologist, and more resemble a fleet, agile animal with a longer neck and tail featuring a whiplash at the end.
And its feet will be 3Dprinted from resin and anatomically accurate, unlike the long toes that have held up the giant skeleton since 1931. Those were based on a Camarasaurus.
“The anatomy of the bones isn’t correct, so we’re not going to bother with them,” said Peter May, who founded RCI in 1987. Instead, the company will create 21st-century feet for the Jurassic dinosaur from models sent from Japan.
The feet are wrong because there were none when the Brontosaurus was found in the Morrison Formation at Como Bluff, Wyo., in 1879. “When we go into the field, we don’t always find a complete skeleton,” said Vanessa Rhue, collection manager of vertebrate paleontology at the Peabody. The museum’s Brontosaurus also had no skull. It’s had two skulls attached at various times.
“These guys always seem to lose their head and their feet,” May said.
Degraded adhesives and plaster
Taking apart a dinosaur skeleton that is 145 million to 200 million years old is delicate work. Being mounted on steel girders and held together with plaster doesn’t make the process of dismantling the fossil easier.
“If there’s any weakness in the bone or the joints have failed, we’ll find out,” May said. The adhesives tend to crystallize “and lose their adhesive ability,” he said.
“Everything gets shrinkwrapped so if any breakage does happen it doesn’t plummet to the ground,” he said.
A couple of spines have fallen off the tail, loosened as scaffolding was erected and the skeleton was jostled by workers using their vibrating saws, hammers and chisels to remove the plaster between the joints. “The adhesive that was holding it had failed and you didn’t find out until it moved a little bit because this thing was built not to move,” May said.
Brontosaurus was sent to Marsh in 25 crates in 1879, according to the Peabody’s website. For a time, it was called Apatasaurus because paleontologists believed they were the same dinosaur and Apatasaurus was the earlier name. But in 2015, a paper established that the two were different dinosaurs and, with a celebration in the Great Hall, the Peabody’s biggest dinosaur got back its name.
The steel frame holding up Brontosaurus was created by bridge builders, May said. The dinosaur is not mounted on steel pipes, which are typical, but “in a very unusual way,” on girders and clamped-together angle bars. “There’s a lot of shims in there, a lot of flat stock,” May said. The mount also is not bolted together, but riveted, as a bridge would be. “It’s the way they knew,” he said.
There’s a great deal of plaster connecting the bones and patching cracks, painted to match the gray bone. And there are steel rods through the “neural canal,” where the spinal cord would have been.
“If they had a break in the bone, they used to use horse glue,” May said. “That’s given up the ghost.” While workers are careful to wrap parts in plastic, fragile fossils do contain cracks. One bone in the right foreleg broke when it was removed, but it’s simple enough to repair at the lab.
“We saw the cracks there. It just separated,” said Matt Fair, RCI’s general manager. “It was broken when it was sitting there. … It’s a clean break and it’s an existing break; it’s not a new one. We try to avoid those.”
The Jurassic Period is far enough back in time that Brontosaurus’ fossilized bones are really solid. “That’s the nice thing about Jurassic bone, just how well fossilized it is,” May said. “You get something from the Cretaceous, it’s just awful.” The Cretaceous Period, the third and last of the Mesozoic Era, was just 145 million to 66 million years ago.
The heaviest part of Brontosaurus is the hip, including the pelvic plate known as the ilium, plus the ischium and pubis. May said that alone weighs 1,500 to 1,800 pounds. “We’ll take off the femur, then we’ll take off the ischium and the pubis,” May said. “We’ll remove all of that, then we’re left with the ilium — the circular bone — and the sacrum and that will come down as one unit.”
A whiplike tail
Much smaller are the vertebrae at the end of the tail, about 6 inches long and 1 inch in diameter, which will stretch out behind the newly mounted Brontosaurus. “Paleontologists surmise they might crack like a whip,” May said. “They find trackways of sauropods like Brontosaurus, but there’s no evidence of tail drag.”
The tail will be longer, as will the neck, once May’s crew adds vertebrae to each end. The final mount will have 15 cervical vertebrae, 10 dorsals along the back, a sacrum composed of five fused vertebrae and 72 in the tail, known as caudals, Rhue said.
Each bone, before it’s removed, will be numbered and tagged with its taxonomic name — Brontosaurus excelsus, one of three species of Brontosaurus — the part of the skeleton and whether it’s from the left or right side, Rhue said. “Once the individual pieces are removed, they can understand the sequence. It’s a big puzzle,” she said.
The dismantling of Brontosaurus, which can be seen through a window on the second floor, will be finished by this week, and then it all will be packed for the trip to Canada.
Once there, the bones will be thoroughly cleaned and plaster removed. Old, failing adhesive will be replaced. Then each piece will be sent to a blacksmith, who will make individual armatures. “What it does is cradle the bone so the bone is safely secured,” May said. “Once all the armatures are done, it will take quite a few months to mount the skeleton.”
A scan and a model
Brontosaurus will be reassembled in the shop, a 3D scan will be made and a one-tenth-scale model will be created and sent to the Peabody, where the staff will decide whether to “lift this leg a little bit or bend the tail a little bit,” May said. The design drawings will be enlarged to full scale and laid out in the Great Hall.
“The architects can establish where the hanging points are going to be,” May said. Steel supports, called upstands, are attached to the main support beams underneath the floor. There will be three cables from the ceiling, one just behind the skull and two on the tail, each capable of supporting 1,000 pounds.
David Skelly, director of the Peabody, said the work of taking apart and shipping the residents of the Great Hall of Dinosaurs, as well as the Hall of Mammals, has gone more quickly than expected since RCI’s team arrived Jan. 21.
“The crew that is doing this work — I’m blown away by them,” he said. “They’ve been part of just about every major North American museum that’s like ours. … They’ve been the folks that have done all the mount work.”
Smithsonian and Jurassic Park
May’s company was hired for the five-year renovation of the Fossil Hall at the Smithsonian National Museum of Natural History in Washington, D.C., where O.C. Marsh spent 10 years as “the first federal paleontologist,” Skelly said.
“The fossils that RCI was working on down there, some of them came from the same digs, the same quarries as the Peabody collection came from,” he said. Marsh divvied up the finds between the two museums.
In London, “they took down a dinosaur mount that had been beloved by the British public and turned it into a moving exhibition that could be moved around the country,” Skelly said. The Diplodocus, known as Dippy, was replaced by the skeleton of a blue whale, the largest animal ever to have lived, which is articulated to dive in midair.
RCI also created sculptures of a Tyrannosaurus rex and an Alamosaurus that appeared in the visitor center in the movie “Jurassic Park.” “You’d never know all the stuff he’s been part of,” Skelly said of May, calling him a “very modest, unassuming guy.”
Skelly said there have been no surprises along the way, even though “these fossils were mounted a long time ago. Some of them are 90 years old and maybe older than that, and people … were figuring it out as they went. They were working in an isolated way and they didn’t keep very good records.”
Skelly said the closing of the Great Hall has met with some disappointment, especially with children of dinosaur-loving age. “The idea of waiting a few years is a big deal to them but I think most people understand what we’re doing and why we’re doing it as well.”
Once the Peabody closes on June 30, it will undergo a major renovation that will add a new central gallery and other exhibit and classroom space.
“One of the ongoing tough parts of the situation to get out to people is we are not closed yet,” Skelly said.