The last Global Extinction in the deep sea - foraminiferal and related data

• Main Authors: Hayward, Bruce William, Kawagata, Shungo, Sabaa, Ashwaq T, Grenfell, Hugh R, Van Kerckhoven, Liesbeth, Johnson, Katherine, Thomas, Ellen
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2022
• Subjects: Deep-sea benthic foraminifera; extinction; mid-Pleistocene climate transition; Antarc*; Antarctica; Foraminifera*; Southern Ocean
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.949555; https://doi.org/10.1594/PANGAEA.949555

Part 1. The Last Global Extinction in the Deep Sea: During the Last Global Extinction (LGE) c. 20% (30 genera, 105 species) of cosmopolitan, mainly deep-sea (600–4000 m), benthic foraminiferal species (excluding unilocular taxa), belonging to seven families, became extinct. During this late Pliocene–middle Pleistocene interval (3.6–0.13 Ma), five families (Chrysalogoniidae, Glandulonodosariidae, Stilostomellidae, Ellipsoidinidae, Pleurostomellidae) were wiped out and one more (Plectofrondiculariidae) was almost wiped out with just one species surviving to the present. Most (76 of 105 species) of these extinctions occurred during the mid-Pleistocene Climate Transition (MPT, 1.2–0.55 Ma) at an extinction rate of 25% myr-1 of the deep-sea benthic foraminifera, compared with a background rate through the Cenozoic of c. 2% myr-1. Most species in the families Chrysalogoniidae, Stilostomellidae, Ellipsoidinidae and Pleurostomellidae had equal levels of abundance throughout their middle bathyal–middle abyssal depth ranges. The Glandulonodosariidae mostly lived at middle bathyal to uppermost abyssal depths and the Plectofrondiculariidae at bathyal to outer shelf depths. These Extinction Group (Ext. Gp) families comprised 30–70% of the deep-sea benthic foraminiferal fauna in the middle to late Eocene. Major declines in their relative abundance and species richness at abyssal depths began in the late Oligocene–Miocene in the Southern Ocean, in the late Miocene in the deep Indian Ocean, in the early Pliocene in the West Pacific, then globally in the late Pliocene at upper abyssal (2300–3000 m) depths and all depths in the Mediterranean Sea. At bathyal depths (900–2200 m) declines and extinctions were largely confined to the Pleistocene. These declines occurred in pulses mostly coinciding with glacial episodes of expansion of polar ice sheets, initially in Antarctica but during the MPT in the Arctic. The LGE preferentially impacted species with specific morphologies (elongate, cylindrical, often uniserial tests) and ...