Cenozoic record of elongate, cylindrical, deep-sea benthic Foraminifera in the North Atlantic and Equatorial Pacific Oceans

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doi: 10.1016/j.marmicro.2010.01.001
Author(s): Hayward, Bruce W.; Johnson, Katie; Sabaa, Ashwaq T.; Kawagata, Shungo; Thomas, Ellen
Author Affiliation(s): Primary:
Geomarine Research, Auckland, New Zealand
Yale University, United States
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, 74(3-4), p.75-95. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. Includes appendix; NSF Grant OCE-720049. 84 refs.; illus., incl. 4 tables, sketch map
Summary: In the late Pliocene-middle Pleistocene a group of 95 species of elongate, cylindrical, deep-sea (lower bathyal-abyssal) benthic foraminifera became extinct. This Extinction Group (Ext. Gp), belonging to three families (all the Stilostomellidae and Pleurostomellidae, some of the Nodosariidae), was a major component (20-70%) of deep-sea foraminiferal assemblages in the middle Cenozoic and subsequently declined in abundance and species richness before finally disappearing almost completely during the mid-Pleistocene Climatic Transition (MPT). So what caused these declines and extinction? In this study 127 Ext. Gp species are identified from eight Cenozoic bathyal and abyssal sequences in the North Atlantic and equatorial Pacific Oceans. Most species are long-ranging with 80% originating in the Eocene or earlier. The greatest abundance and diversity of the Ext. Gp was in the warm oceanic conditions of the middle Eocene-early Oligocene. The group was subjected to significant changes in the composition of the faunal dominants and slightly enhanced species turnover during and soon after the rapid Eocene-Oligocene cooling event. Declines in the relative abundance and flux of the Ext. Gp, together with enhanced species loss, occurred during middle-late Miocene cooling, particularly at abyssal sites. The overall number of Ext. Gp species present began declining earlier at mid abyssal depths (in middle Miocene) than at upper abyssal (in late Pliocene-early Pleistocene) and then lower bathyal depths (in MPT). By far the most significant Ext. Gp declines in abundance and species loss occurred during the more severe glacial stages of the late Pliocene-middle Pleistocene. Clearly, the decline and extinction of this group of deep-sea foraminifera was related to the function of their specialized apertures and the stepwise cooling of global climate and deep water. We infer that the apertural modifications may be related to the method of food collection or processing, and that the extinctions may have resulted from the decline or loss of their specific phytoplankton or prokaryote food source, that was more directly impacted than the foraminifera by the cooling temperatures. Abstract Copyright (2010) Elsevier, B.V.
Year of Publication: 2010
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 10 Paleontology, Invertebrate; Atlantic Ocean; Benthic taxa; Cenozoic; DSDP Site 317; DSDP Site 548; DSDP Site 608; Deep Sea Drilling Project; Deep-sea environment; East Pacific; Equatorial Pacific; Extinction; Faunal list; Faunal studies; Foraminifera; Goban Spur; IPOD; Invertebrata; Leg 143; Leg 162; Leg 167; Leg 172; Leg 33; Leg 80; Leg 94; Manihiki Plateau; Marine environment; Microfossils; Mid-Pacific Mountains; Nodosariacea; Nodosariidae; North Atlantic; North Pacific; Northeast Atlantic; Northeast Pacific; ODP Site 1012; ODP Site 1055; ODP Site 865; ODP Site 980; ODP Site 982; Ocean Drilling Program; Pacific Ocean; Paleoclimatology; Paleoecology; Paleoenvironment; Pleurostomellidae; Protista; Rockall Bank; Rotaliina; South Pacific; Southeast Pacific; Stilostomellidae
Coordinates: N321658 N321658 W1182302 W1182302
N182624 N182626 W1793320 W1793321
S110006 S110005 W1621546 W1621547
N552906 N573100 W0144208 W0155200
Record ID: 2011003716
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands