A basic tenet underpinning scientists’ understanding of extinction is that more abundant species persist longer than their less abundant counterparts. A new study reveals a much more complex relationship. A team of scientists analyzed more than 46,000 fossils from 52 sites and found that greater numbers did indeed help clam-like brachiopods survive the Ordovician extinction. Surprisingly, abundance did not help brachiopod species persist for extended periods outside of the extinction event.