Citizens turn deep time hunters

Mol (right) with Arie van den Ban, founder of Historyland, beside a reconstruction of a southern mammoth at the Historyland museum in Hellevoetsluis, the Netherlands. ‘Citizen paleontologists’ can keep the fossils they uncover around Europe’s largest port. — Ilvy Njiokiktjien/The New York Times

AFTER hours of combing the long sweep of beach skirting Rotterdam’s vast harbour, Cock van den Berg finally spotted something that made him stop.

The retired Dutch engineer had been sifting through the wet sand all morning when he fished out a polished black stone, no bigger than an acorn, with two neat punctures. He held it out to Dick Mol, one of the Netherlands’ best-known Ice Age specialists.