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Which groups of bryozoans disappeared during the Permian extinction?

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Line graph showing the number of marine animal families from the Precambrian era to the present, with illustrations of key groups such as trilobites, ammonoids, marine reptiles, and diatoms. The graph highlights major extinction events and a rise to 1,900 living families today. — Permian extinction The diversity of marine animal families since late Precambrian time. The data for the curve comprise only those families that are reliably preserved in the fossil record; the 1,900 value for living families also includes those families rarely preserved as fossils. The several pronounced dips in the curve correspond to major mass-extinction events. The most catastrophic extinction took place at the end of the Permian Period.

During the Permian extinction, the cryptostomate and fenestrate groups of bryozoans disappeared. These groups were notable for having inhabited many Carboniferous and Permian reefs prior to the crisis. While bryozoans as a whole experienced significant declines by the end of the Permian Period, these specific orders did not survive the extinction event.12