It's been just over a year since the National Fossil Halls closed for renovation, and we've reached an important landmark; the last fossils have been taken out of the exhibit, and numerous models, dioramas and paintings have been removed as well. Demolition is under way.
The final dinosaur specimens to exit the halls were the tail and hind limbs of Corythosaurus casuarius (USNM 15493) and the full skeleton of Ceratosaurus nasicornis (USNM 4735). Both had been exhibited on the wall as "plaque mounts," with most of the bones partly embedded in plaster. Neither was small enough to pass out of the exhibit intact.
Sheathed in plywood to protect the fossil from overhead work, the frame holding the Corythosaurus was detached from the wall and lifted onto the floor.
This 1920 drawing from a scientific publication by Charles W. Gilmore shows the reconstructed skeleton of Ceratosaurus as it was positioned for display. The mount was first exhibited in 1910.
The empty plaque after the framework was cut and chunks of skeleton were extracted from the plaster.
Specimens of Ceratosaurus are rare, and ours, found in the 1880s, was the first discovered. Because of its scientific and historical importance, we will preserve the original bones in our collections and make casts (exact replicas) from them for exhibit in the renovated Fossil Halls. Stay tuned for future posts about molding and casting the individual bones and building the new skeletal mount.
The last mammals to leave the Fossil Halls were Harlan's ground sloth, Paramylodon harlani (USNM 15164), and the Stegomastodon arizonae (USNM 10707). These large specimens are rotating out of the exhibit lineup and entering storage, where they will be available for scientific study. But first they must be conserved and dismantled, and appropriate archival storage jackets and trays must be built for all of the bones.
Taking off the ribs. Too large to fit in the elevator, the skeleton was partly dismantled before removal from the exhibit halls.
Many hands make less-heavy work. The Harlan's ground sloth was just small enough to fit through all the doorways between the exhibit and the lab where it would be dismantled.
The sloth's arm and hand bones are shown in the new archival storage we are creating for specimens not returning to the renovated exhibit.
Preparator Alan Zdinak sets up to build a storage jacket for the ground sloth's pelvis. Read more about storage jackets in an earlier post.
Fossils weren't the only things that needed to make way for the renovation. The photo below shows the removal of one of many paintings from the exhibit.
We are keeping many of the models that helped bring the Fossil Halls to life for our visitors, but some models have been given to other museums. The life-sized models of the pterosaur Quetzalcoatlus (shown below) and Stegosaurus, for example, were trucked to the Museum of the Earth in Ithaca, New York. These models, too, had to be cut into pieces to fit through the doors, so they will have to be reassembled before they can be exhibited.
Read earlier posts about dismantling the Fossil Halls here. Future posts in this renovation series will include highlights of our work on specimens returning to exhibit in 2019.