Origination, extinction, invasion, and extirpation components of the brachiopod latitudinal biodiversity gradient through the Phanerozoic Eon

Abstract. The geographic distribution of brachiopod genus occurrences over the Phanerozoic shows that secular declines in origination and extinction rates were paralleled by increases in invasion and extirpation rates. Origination and extinction rates declined in two phases, the first from the Cambrian to latest Permian Periods and the second from the latest Permian Period to the present, which were accompanied by concomitant increases in invasion and extirpation rates. In addition to the temporal correlation, an inverse correlation was also weakly evident among time-averaged latitudinal gradients of rates. Compared with faunas at higher latitudes, low-latitude faunas experienced higher origination and extinction rates, and lower invasion and extirpation rates. We suggest that progressive increases in migration ability lowered origination and extinction rates because species that were better equipped to track a preferred habitat, for example, by the ability to disperse larvae over large distances, were le...