Hantkeninid depth adaptation; an evolving life strategy in a changing ocean

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doi: 10.1130/0091-7613(2000)28<87:HDAAEL>2.0.CO;2
Author(s): Coxall, Helen K.; Pearson, Paul N.; Shackleton, Nicholas J.; Hall, Mike A.
Author Affiliation(s): Primary:
University of Bristol, Department of Earth Sciences, Bristol, United Kingdom
University of Cambridge, Cambridge, United Kingdom
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 28(1), p.87-90. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. 28 refs.; illus.
Summary: The interplay between evolution, paleoecology, and environmental change is examined in a geochemical study of a group of Eocene planktonic foraminifera. The hantkeninids, which are well-known biostratigraphic index fossils, underwent spectacular long-term evolution in the middle and upper Eocene (49.0-33.7 Ma), a time when major global climate and oceanic changes were occurring. We use oxygen and carbon isotope analysis of their shell calcite to investigate how their habitat changed as they evolved. The hantkeninids originated in a deep-water oxygen-minimum environment, but migrated into fully oxygenated near-surface waters as global temperatures decreased and water-column stratification declined. This change in depth ecology coincided with pronounced morphological evolution, involving changes in chamber shape and degree of inflation, and modification of the primary aperture. These developments are considered to be adaptations to a near-surface habitat.
Year of Publication: 2000
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 10 Paleontology, Invertebrate; 12 Stratigraphy, Historical Geology and Paleoecology; Adaptation; Atlantic Ocean; Benthic taxa; Biochemistry; Biologic evolution; C-13/C-12; Calcite; Campeche Scarp; Carbon; Carbonates; Cenozoic; DSDP Site 549; DSDP Site 94; Deep Sea Drilling Project; Eocene; Foraminifera; Goban Spur; Gulf of Mexico; Habitat; Hantkeninidae; IPOD; Invertebrata; Isotope ratios; Isotopes; Leg 10; Leg 143; Leg 80; Microfossils; Mid-Pacific Mountains; Morphology; North Atlantic; North Pacific; O-18/O-16; ODP Site 865; Ocean Drilling Program; Ocean circulation; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleoecology; Paleoenvironment; Paleogene; Paleolatitude; Paleomagnetism; Pelagic environment; Planktonic taxa; Protista; Range; Stable isotopes; Tertiary; Tests
Coordinates: N182624 N182626 W1793320 W1793321
N490516 N490518 W0130552 W0130554
N243138 N243138 W0882809 W0882809
Record ID: 2000018585
Copyright Information: GeoRef, Copyright 2018 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States