Palaeoceanographic implications of genetic variation in living North Atlantic Neogloboquadrina pachyderma
The shells of the planktonic foraminifer Neogloboquadrina pachyderma have become a classical tool for reconstructing glacial-interglacial climate conditions in the North Atlantic Ocean1-3. Palaeoceanographers utilize its left- and right-coiling variants, which exhibit a distinctive reciprocal temper...
| Published in: | Nature |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Nature Publishing Group
2003
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1842/680 https://doi.org/10.1038/nature01778 |
| Summary: | The shells of the planktonic foraminifer Neogloboquadrina pachyderma have become a classical tool for reconstructing glacial-interglacial climate conditions in the North Atlantic Ocean1-3. Palaeoceanographers utilize its left- and right-coiling variants, which exhibit a distinctive reciprocal temperature and water mass related shift in faunal abundance both at present and in late Quaternary sediments1,2,4,5. Recently discovered cryptic genetic diversity in planktonic foraminifers6-8 now poses signifi- cant questions for these studies. Here we report genetic evidence demonstrating that the apparent 'single species' shell-based records of right-coiling N. pachyderma used in palaeoceanographic reconstructions contain an alternation in species as environmental factors change. This is reflected in a speciesdependent incremental shift in right-coiling N. pachyderma shell calcite d 18O between the Last Glacial Maximum and full Holocene conditions. Guided by the percentage dextral coiling ratio, our findings enhance the use of d 18O records of rightcoiling N. pachyderma for future study. They also highlight the need to genetically investigate other important morphospecies to refine their accuracy and reliability as palaeoceanographic proxies. |
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