Early Triassic recovery of the brachiopod faunas from the end-Permian mass extinction: A global review

Brachiopod faunas in Lower Triassic deposits from Spitzbergen, Primorye of Russia, Japan, Mangyslak of Kazakhstan, Alpine Europe, the Caucasus, the Middle East, the Himalaya, South China, New Zealand, and western USA are taxonomically and stratigraphically reviewed. They comprise survivors of the end-Permian extinction and taxa originating in the Early Triassic. Origination of the Mesozoic-type taxa represents the recovery of Early Triassic brachiopods. The initial recovery of brachiopod faunas began in the late Griesbachian, and the time interval between the end of extinction and the onset of the recovery of brachiopods is much shorter than previously suspected. The Early Triassic recovery of brachiopod faunas is characterized by widespread brachiopod dispersal, multiprovincialism, and the presence of rare Lazarus genera at that time. Taxonomic selectivity of the recovery brachiopod faunas favors the rhynchonellids. The re-population of post-extinction brachiopods varies geographically: there is a preference for regions either previously barren of latest Permian taxa or regions where the pre-extinction Changhsingian and surviving brachiopods are very rare. This unique biogeographic selectivity is probably partly responsible for the impoverished nature of brachiopod faunas in the Triassic (even Mesozoic) oceans. Five intervals of extinction, survival, survival-recovery, recovery-dispersal, and radiation are recognized based on variations in brachiopod faunas from the latest Permian to the Early Triassic. A dramatic reduction in brachiopod diversity at the end-Permian mass extinction is followed by several stepwise declines in diversity in the survival interval, the time during which the surviving brachiopods are dominated by geographically widespread generalist faunas that adapted to a wide variety of environments. The survival interval was followed by a slow re-population of new lineages dominated by progenitor taxa.