Scientists were in a swivet last month when they learned that Butterfields, a San Francisco-based auction house, was putting the 200-million-year-old fossil, a glider with the wingspan of a large dragonfly, up for sale. Now they are grateful to Bay Area businessman Dick Spight, who stepped in with $167,000 so he could donate the fossil to the museum. "It's come home," says paleontologist Kevin Padian of the University of California, Berkeley, who helped arrange the transaction.

Scientists have seized upon the sale of Icarosaurus as yet another example of the need for measures to keep unique specimens in the public domain. Berkeley paleontologist Mark Goodwin said putting Icarosaurus on the block was a "highly unethical event" that will only spur commercialization and fossil theft.

The fossil was discovered in a shale quarry near North Bergen, New Jersey, in 1960 by 16-year-old Alfred Siefker and two friends. Siefker loaned it to the museum, but reclaimed it in 1989. Needing money to pay medical bills, he reportedly tried to sell the fossil to several museums, but his asking price was too high. Finally, on 27 August it was purchased--at half the price Butterfields estimated it would bring.