Early Eocene deep-sea benthic foraminiferal faunas; recovery from the Paleocene Eocene Thermal Maximum extinction in a greenhouse world

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doi: 10.1371/journal.pone.0193167
Author(s): Arreguín-Rodríguez, Gabriela J.; Thomas, Ellen; D'haenens, Simon; Speijer, Robert P.; Alegret, Laia
Author Affiliation(s): Primary:
Universidad de Zaragoza, Departamento de Ciencias de la Tierra, Saragossa, Spain
Other:
Yale University, United States
Katholieke Universiteit Leuven, Belgium
Volume Title: PLoS One
Source: PLoS One, 2018(e0193167). Publisher: Public Library of Science, San Francisco, CA, United States. ISSN: 1932-6203
Note: In English. Includes appendix; NSF Grant OCE-1536611. 206 refs.; illus., incl. 5 tables, sketch map
Summary: The early Eocene greenhouse world was marked by multiple transient hyperthermal events. The most extreme was the Paleocene-Eocene Thermal Maximum (PETM, ∼56 Ma), linked to the extinction of the globally recognised deep-sea benthic foraminiferal Velasco fauna, which led to the development of early Eocene assemblages. This turnover has been studied at high resolution, but faunal development into the later early Eocene is poorly documented. There is no widely accepted early Eocene equivalent of the Late Cretaceous-Paleocene Velasco fauna, mainly due to the use of different taxonomic concepts. We compiled Ypresian benthic foraminiferal data from 17 middle bathyal-lower abyssal ocean drilling sites in the Pacific, Atlantic and Indian Oceans, in order to characterise early Eocene deep-sea faunas by comparing assemblages across space, paleodepth and time. Nuttallides truempyi, Oridorsalis umbonatus, Bulimina trinitatensis, the Bulimina simplex group, the Anomalinoides spissiformis group, pleurostomellids, uniserial lagenids, stilostomellids and lenticulinids were ubiquitous during the early Eocene (lower-middle Ypresian). Aragonia aragonensis, the Globocassidulina subglobosa group, the Cibicidoides eocaenus group and polymorphinids became ubiquitous during the middle Ypresian. The most abundant early Ypresian taxa were tolerant to stressed or disturbed environments, either by opportunistic behavior (Quadrimorphina profunda, Tappanina selmensis, Siphogenerinoides brevispinosa) and/or the ability to calcify in carbonate-corrosive waters (N. truempyi). Nuttallides truempyi, T. selmensis and other buliminids (Bolivinoides cf. decoratus group, Bulimina virginiana) were markedly abundant during the middle Ypresian. Contrary to the long-lived, highly diverse and equitable Velasco fauna, common and abundant taxa reflect highly perturbed assemblages through the earliest Ypresian, with lower diversity and equitability following the PETM extinction. In contrast, the middle Ypresian assemblages may indicate a recovering fauna, though to some extent persistently disturbed by the lower-amplitude Eocene hyperthermals (e.g., Eocene Thermal Maximum 2 and 3). We propose the name 'Walvis Ridge fauna' for future reference to these Ypresian deep-sea benthic foraminiferal assemblages.
Year of Publication: 2018
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Assemblages; Atlantic Ocean; Benthic taxa; Blake Nose; Blake Plateau; Broken Ridge; Cenozoic; DSDP Site 401; DSDP Site 550; Deep Sea Drilling Project; Deep-sea environment; Demerara Rise; East Pacific; Electron microscopy data; Eocene; Equatorial Atlantic; Equatorial Pacific; Foraminifera; Greenhouse effect; Habitat; IPOD; Indian Ocean; Leg 113; Leg 121; Leg 143; Leg 171B; Leg 198; Leg 199; Leg 207; Leg 208; Leg 48; Leg 80; Lower Eocene; Marine environment; Maud Rise; Microfossils; Mid-Pacific Mountains; Morphology; North Atlantic; North Pacific; Northeast Pacific; Northwest Atlantic; Northwest Pacific; ODP Site 1051; ODP Site 1209; ODP Site 1210; ODP Site 1211; ODP Site 1212; ODP Site 1215; ODP Site 1220; ODP Site 1221; ODP Site 1258; ODP Site 1262; ODP Site 1263; ODP Site 689; ODP Site 690; ODP Site 752; ODP Site 865; Ocean Drilling Program; Pacific Ocean; Paleobathymetry; Paleocene-Eocene Thermal Maximum; Paleoclimatology; Paleoenvironment; Paleogene; SEM data; Shatsky Rise; South Atlantic; Southern Ocean; Taxonomy; Tertiary; Tests; Walvis Ridge; Weddell Sea; West Atlantic; West Pacific; Ypresian
Coordinates: S290000 S270000 E0030000 E0013000
S305329 S305328 E0933440 E0933439
N313400 N374800 E1624600 E1571500
N074500 N260500 W1350000 W1480000
Record ID: 2018041930
Copyright Information: GeoRef, Copyright 2018 American Geosciences Institute.