A chronofauna is a geographically restricted collection of interacting animal populations that maintains its base structure over a long period of time. We describe a simple computational method that can identify candidate chronofaunas on the basis of presence-absence matrices only: A candidate chronofauna is a collection of sites that share an exceptionally large number of taxa with the defining site of the chronofauna. We show examples of candidate chronofaunas in the NOW data (see  http://www.helsinki.fi/science/now).