The Best Guide
What the hadrosaur, called Dead Sheep 148, does have is ossified tendons, long tubular fossils about the width of a pencil. These are tendons that turned to bone. You find them in some birds, like turkeys, but not in others, like chickens. Scientists can still only guess their purpose.
"Most animals don't have ossified tendons. They are pretty unique among hadrosaurs," said J.P. Cavigelli, prep lab manager at the Tate Geological Museum. He named the hadrosaur after finding one of its bones on a ranch near Lusk, near a dead sheep sporting a tag numbered "148."
This specimen — still encased in a 1,500-pound rock, plaster and expanding foam — will show these tendons, the pile of bones as paleontologists found them, laid out pretty close to what they would have been in life.
But first, Cavigelli has to get it to the display stand, located in the back corner of the museum.
"We'll take it all the way to the mammoth skull then we'll turn," Cavigelli said recently to his dinosaur-moving muscle, longtime Tate volunteers Steve Pfaff and Dwaine Wagoner.
"Watch the glass."
Consider the journey every fossil has to take before you see it in the museum. Each one walked, or swam, or buried itself in the mud at some time or another. It had to die, then fossilize. It had to be found, excavated, shipped and cleaned. It was probably examined and studied, measured and weighed. Someone, at some time, decided that the fossil was worth showing — that people like you might walk by and be interested, learn something about the prehistoric history of the world in which they live.
The journey for this hadrosaur started 65 million years ago when it died, falling into a Cretaceous stream. The current pushed it up against a fallen tree and within a matter of weeks, Cavigelli figures, the head and tail decayed off and were swept away by the river.
Layer after layer of sand covered the hadrosaur. It fossilized, mountains pushed upward, and erosion uncovered a part of it once again. In 2005, Cavigelli stumbled upon it — and the 18-foot section of the ancient tree — near Lance Creek in eastern Wyoming.
It took another two years to get the chunk of rock to the Tate, another four for Tate staff and volunteers to clean it up. The museum was excavating Dee the Mammoth at the same time, and often the hadrosaur took a back seat. Dee at least had a skull.
True, this hadrosaur will never stand alongside Dee and it won't be as big a draw. But it has much to teach.
"I think we are really trying to show people what these specimens look like when they come out of the ground," said Deanna Schaff, director of museums at Casper College. "Sometimes I think museum specimens are almost too polished and too perfect."
Dead Sheep 148 will show some of the process of paleontology. It will stay encased in the rock in which it was found, protected by plaster and super-expanding foam.
It recently took two hours just to get it onto the display board. In distance, it was a short trip: out of the prep lab, around two corners to an open spot in the museum with a ceiling high enough to fit the tripod and winch.
Logistically it was a bit more complicated.
The plan was to go something like this: Strap the rock to the winch, dangling it a foot or so over the table. Slide under the custom-made display board, lower the rock gently down, move it back into the prep lab, and apply the fast-drying, expandable foam to cushion and secure it to place. Once dry, and when all the display text and signs have been finished, move it again to its permanent display area.
"Oh, my," said Patti Wood Finkle when straps finally pulled taut and the hadrosaur dangled in the air. She had, perhaps, been standing in the wrong place at the wrong time, recruited to steady one end of the rock, the end that threatened to topple down, possibly damaging the fossil and taking out the T-Rex display at back.
"Is it getting heavy?" Cavigelli asked.
"Ya think?" Finkle replied.
"Keep an eye on that crack" in the fossil, Cavigelli said.
No pressure.
As exhibits specialist, Finkle designed the exhibit for this hadrosaur and will write the text and signage. For education purposes, she likes that it will be displayed as is.
"All the museums have replicas of the best, coolest and most articulated specimens. This one is in its field jacket. It lets people see what paleontologists see in the field," she said.
An animal "doesn't die and all the pieces fall perfectly in line."
In the next couple of months, more foam will be applied, securing it to its new display board. Sometime this summer, it will be moved again out into the museum for permanent display. You may read that this particular hadrosaur might be an Edmontosaurus, but without a head, there's no way to be sure. Maybe you'll realize that that is what paleontology is often about: Working with bones instead of skeletons, years of work in the field and in the lab, jury-rigging displays so that they work in the space available.
Author: Kristy Gray | Source: Desert News [May 18, 2011]
Thursday, May 19, 2016