PHILADELPHIA — The Academy of Natural Sciences, a Philadelphia institution known for its dinosaur skeletons and scientific collections, closed to the public Sept. 30, less than two years before its 200th anniversary. The shutdown followed an announcement on Sept. 1 that the museum would close at month’s end. Families flocked to visit in its final weeks, while former staff, scientists and residents organized rallies and a “Save the Academy” campaign. An online petition gathered more than 114,000 signatures. The museum was founded in 1812 and opened to the public in 1828. In 1868, it became the first institution in the world to display a dinosaur skeleton. Its exhibits have included mammal dioramas and live animals, alongside a scientific collection of more than 19 million specimens. That collection includes fossils gathered by Thomas Jefferson, plant samples collected by Lewis and Clark, and 73,000 holotype specimens — preserved reference samples used by scientists to identify and name species. Drexel University has said researchers and students will retain access, but the arrangement for general visitors remains unclear. Drexel assumed financial responsibility for the Academy in 2011. The university cited rising costs and declining attendance after the pandemic in explaining the closure. Museum attendance surged during the final weeks, with revenue more than 20 times higher than in September 2025. The William Penn Foundation offered a year of bridge funding less than a week before the closing date, giving the institutions time to explore longer-term options. Drexel said it was considering working with the foundation but would need a plan for the museum’s long-term sustainability before considering reopening. Isa Betancourt, a former Academy entomology department employee who returned to Philadelphia to help organize the campaign, said the abrupt, one-month notice frustrated supporters. “It’s like the leadership didn’t even try to keep it open,” she said. Drexel said it remained “deeply committed to protecting the Academy of Natural Sciences’ extraordinary legacy.” The university and museum had been discussing their relationship earlier this year. Drexel sought a full merger that would give it the building, endowment and collections, according to reporting cited in the closure debate. The closure is also raising questions about the future of the Academy’s century-and-a-half-old building. Philadelphia City Council has proposed zoning changes that could make a sale or conversion to another use more difficult, and plans special hearings to examine how the museum reached the point of closing and what options might remain. The legislation authorizing the hearings gives council subpoena power over Drexel. “We need to know how this came to be,” Councilmember Nina Ahmad said. “What were the levers that created this decision, and how do we undo that decision?” The Academy’s troubles unfolded amid broader financial pressure on museums and scientific institutions. Drexel has faced budget challenges, while the Academy cut staff, reduced hours and canceled its 2026 summer camp program as attendance fell. Museum advocates say reopening after a closure may be more difficult than intervening before an institution shuts its doors.