Fossil Hall in the Smithsonian National Museum of Natural History — one of the most popular attractions in Washington — goes dark at the end of April and remains closed until 2019, writes Gretel Johnston

Ask a Washingtonian where to find the city’s famous collection of dinosaurs, and many in the US capital would be tempted to joke: in the US Senate.
Washington’s most famous fossils are not in the legislature, but in the Fossil Hall in the Smithsonian National Museum of Natural History, a space about to undergo a major renovation scheduled to take five years.
The exhibition — one of the most popular attractions in Washington — goes dark at the end of April and remains closed until 2019.
The Fossil Hall will be missed by schoolchildren and scientists alike, but museum officials are sure it will be worth the wait.
When the exhibit reopens, it will be “entirely changed,” said Matthew Carrano, curator of dinosaurs at the museum.
The major change will be a long arching path that goes back in time and concludes with the origins of life on earth. As visitors stroll down the path they will be able to see the highlights, Carrano said. By going into the exhibits along the path, they will find out the details of the palaeontological periods.
The new exhibit will allow the museum to show off the dinosaurs and the fossils it has, including some of the stars of the palaeontological record, and “present them in a way that’s exciting and dramatic,” Carrano said.
“We want it to be more than a curiosity cabinet.”
The current exhibit, contained in a wing of the massive museum building in downtown Washington, DC, is more like a maze.
Just beyond the entrance, visitors are immediately confronted by nearly all its marquee skeletons. A Tyrannosaurus rex looms large. Though it is only a partial fossil, it is posed life-like in mid stride and its vicious jagged teeth are a stark reminder that it was a carnivore.
Nearby is the skeleton of a diplodocus, a large plant eater that lived in a different era — the late Jurassic Period — and by comparison a much more docile animal. Dead 145 million years, the 30-metre-long fossil has been on display at the museum since 1931, when the dinosaur exhibit was known as the Hall of Extinct Monsters.
Along the periphery of the room are a triceratops and a stegosaurus, all posed in small spaces in the shadow of the larger skeletons with many other smaller skeletons all around — on the walls and hanging from the ceiling.
In every direction there are ancient bones from the fossil record viewed by estimated 5.5 million people who visit the exhibit annually.
All the specimens were found somewhere in the United States and were acquired by the museum, which first opened in 1910 and has been receiving dinosaur remains piecemeal since then. There are now an estimated 46 million fossils in the museum’s collection.
After the Fossil Hall closes, teams of palaeontologists will begin the painstaking task of dissembling the skeletons bone by bone. Each will be examined and prepared for the new exhibit using modern conservation techniques.
Some will be transported elsewhere to be studied while the renovation is ongoing.
Palaeontologists who work for the museum hope the process will help them better understand how much of the skeletons are real fossil bone and how much is restorers’ plaster or another filler material.
In its current state the exhibit has been essentially unchanged for more than 30 years.
Museum officials had wanted to update it, but lacked the money for a total renovation. That changed about a year ago when American billionaire David H Koch donated 35 million dollars for the renovation, which the museum said will be the largest and most complex in the museum’s history.
Koch’s gift will cover more than three-quarters of the total $45 million estimated cost of the renovation. Koch is better known for giving to political causes, but he previously donated $15 million to the museum for its Hall of Human Origins.
Just before the exhibit closes on April 28, the museum will welcome a second Tyrannosaurus rex that museum officials say is a “spectacular” specimen. The fossil, known as the Wankel T. rex, was found by rancher Kathy Wankel on federal land in Montana in 1988.
One reason the skeleton is so interesting is that about 85 per cent of it was recovered, making it one of the most complete T. rex specimens ever found.
It was displayed at a Montana museum from 1990 through 2011. Then last year the National Museum of Natural History negotiated a 50-year loan of the skeleton with the US Army Corps of Engineers.
When the new exhibit opens, the Wankel T. rex will be one of its centerpieces, museum officials said.
Before it can go on display, however, the Wankel T. rex will receive some tender loving care. Palaeontologists want to further study the specimen and at the same time work to conserve it and also photograph and scan it.
The T. rex has always captured the imagination of just about everyone interested in dinosaurs, because at more than 13 metres in length and weighing as much as 5 tons, it was one of the largest carnivorous animals ever to live on land.
It roamed in western North America 68-66 million years ago alongside herbivourous donosaurs such as the triceratops and the duck-billed edmontosaurus.
To ensure that dinosaurs still roam in Washington during the five-year closure of the exhibit, the museum plans a temporary exhibit opening next year in its lobby. This will feature fossils from the last days of the American dinosaurs.
Museum director Kirk Johnson, a palaeontologist, told the Washington Post the exhibit’s long closure would be traumatic for him, so he can understand that the kids who visit Washington will be sad to miss the chance to wander among the specimens.
But he said the five years of the renovation are going to “fly by.” Perhaps, the kids should consider how short that amount of time is compared with the palaeontological record that reaches back millions and millions of years into the history of the earth. — DPA