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Which marine invertebrates suffered the greatest losses during the Permian extinction?
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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, shallow warm-water marine invertebrates experienced the most protracted and severe losses. The groups that suffered the greatest declines included:1
- Trilobites: This group of arthropods made their final appearance in the fossil record at the end of the Permian.12
- Corals: Both rugose and tabulate corals became extinct by the end of the Paleozoic Era.12
- Echinoderms: Two major groups, the blastoids and crinoids, were hit particularly hard. Blastoids, which had persisted in some regions until the end of the period, disappeared entirely.12
- Brachiopods: Several superfamilies, including productaceans, chonetaceans, and richthofeniaceans, vanished.2
- Bryozoans: Cryptostomate and fenestrate groups, which were common in Paleozoic reefs, did not survive the crisis.2
- Foraminiferans: Fusulinid foraminiferans, which served as important index fossils, also went extinct.2
Overall, these extinctions reduced marine invertebrate diversity to roughly 5 percent of their Guadalupian maxima, marking their lowest diversity levels since the end of the Ordovician Period.1