Palaeozoic brachiopod extinctions, survival and recovery: patterns within the rhynchonelliformeans

The brachiopod‐dominated seabeds of the Palaeozoic were modified by a series of biotic extinctions and recoveries. The ecologic and taxonomic dynamics of the Cambrian and Paleozoic Evolutionary Faunas were interrupted during the late Cambrian, end‐Ordovician, late Devonian and end‐Permian by a multiple series of extinctions. While the balance between the deltidiodont and cyrtomatodont rhynchonelliformeans was maintained during the Palaeozoic, the dominant role of the orthides and strophomenides during the early to mid‐Palaeozoic was usurped by the productides during the late Palaeozoic. The deltidiodont morphology did not survive the end‐Permian extinctions; the modern articulated brachiopod fauna is dominated by cyrtomatodonts with crurae and loops. Nevertheless, a recurring trend is the long‐term success of brachiopod taxa with widespread distributions and the demise of the more specialized and highly adapted morphs having more restricted distributions commonly evolved during interregna between phases of extinction.