The Koch gift is the largest single donation to the Natural History Museum and the fifth largest in Smithsonian history.
Koch, a member of the museum’s advisory board for the past five years, previously gave $15 million to the museum’s David H. Koch Hall of Human Origins.
The subject matter of both human origins and dinosaurs has always fascinated him, he said.
“It goes way back,” Koch said in a telephone interview from New York. “I went to my first dinosaur hall with my father and twin brother. We went to the American Museum of Natural History, and I was blown away by the dinosaurs.”
Some of the specimens in the Smithsonian’s dinosaur exhibit have been part of the gallery since the building opened 100 years ago.
“It is obvious that the dinosaur hall is obsolete,” Koch said. “This phenomenal Natural History Museum needs to have an updated dinosaur hall. They are the most popular in any natural history museum.”
He felt compelled to respond when the topic came up of raising money for what will be the biggest and largest renovation at the museum.
“This is too tempting. This is my sweet spot,” he said.
Thursday was Koch’s 72nd birthday, but the gift wasn’t timed with any personal celebration, he said.
“This is an independent coincidence,” he said. “I had a major birthday two years ago. I think the party my wife gave is good for 10 years.”
Koch, whose worth was listed as $25 billion in March 2012 by Forbes, has given broadly to political, health and arts organizations. He’s given to the Metropolitan Museum of Art, the American Ballet Theater and Lincoln Center.
In 2006, he gave $20 million to the American Museum of Natural History in New York for its dinosaur exhibit, the halls where he first fell in love with dinosaurs.
In 2008, he donated $100 million for the renovation for the State Theater of New York at Lincoln Center.
“For the past 10 years, we’ve been working on redoing the exhibitions. There is exciting science that we and other paleobiologists have been doing, and we want to showcase the latest,” said Cristian Samper, director of the Natural History Museum.
The museum holds 46 million fossils and the current presentation is one of the museum’s top draws.
The dinosaur hall, which covers 25,000 square feet, has needed critical physical and scholarly updating for years. The display is more than 30 years old.
The existing hall will close in spring 2014 and the target date for the renovation completion is 2019. The total cost of the work is estimated at $45 million.
The museum plans to move dinosaur specimens to other parts of the museum for public viewing.