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| Payne, Jonathan L.; Groves, John R.; Jost, Adam B.; Thienan Nguyen,; Moffitt, Sarah E.; Hill, Tessa M.; Skotheim, Jan M.. |
| Atmospheric hyperoxia, with pO2 in excess of 30%, has long been hypothesized to account for late Paleozoic (360250 million years ago) gigantism in numerous higher taxa. However, this hypothesis has not been evaluated statistically because comprehensive size data have not been compiled previously at sufficient temporal resolution to permit quantitative analysis. In this study, we test the hyperoxia-gigantism hypothesis by examining the fossil record of fusulinoidean foraminifers, a dramatic example of protistan gigantism with some individuals exceeding 10 cm in length and exceeding their relatives by six orders of magnitude in biovolume. We assembled and examined comprehensive regional and global, species-level datasets containing 270 and 1823 species,... |
| Tipo: Text |
Palavras-chave: Body size; Carboniferous; Cope's Rule; Foraminifera; Oxygen; Permian. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00265/37626/35865.pdf |
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| Moffitt, Sarah E.; Hill, Tessa M.; Ohkushi, Kenichi; Kennett, James P.; Behl, Richard J.. |
| Here we present a history of deoxygenation of upper intermediate waters during the last deglaciation from Santa Barbara Basin (SBB), based on quantitative analyses of benthic foraminiferal assemblages, from a new shallow piston core above basin sill depth (MV0811-15JC, 418 m), and previously described sequences in the deeper basin (MD02-2504, 481 m and MD02-2503, 570 m). We document a 152 m depth transect of benthic foraminiferal assemblages to extract changing community structure (density, diversity, and evenness) and improve paleoenvironmental interpretation of late Quaternary vertical oscillations in the upper boundary of the oxygen minimum zone (OMZ). Close interaction between changes in open margin OMZ and that of the restricted SBB is documented... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00291/40226/38698.pdf |
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| Moffitt, Sarah E.; Moffitt, Russell A.; Sauthoff, Wilson; Davis, Catherine V.; Hewett, Kathryn; Hill, Tessa M.. |
| Climate-driven Oxygen Minimum Zone (OMZ) expansions in the geologic record provide an opportunity to characterize the spatial and temporal scales ofOMZ change. Here we investigate OMZ expansion through the global- scale warming event of the most recent deglaciation (18- 11 ka), an event with clear relevance to understanding modern anthropogenic climate change. Deglacial marine sediment records were compiled to quantify the vertical extent, intensity, surface area and volume impingements of hypoxic waters upon continental margins. By integrating sediment records (183-2,309 meters below sea level; mbsl) containing one or more geochemical, sedimentary or microfossil oxygenation proxies integrated with analyses of eustatic sea level rise, we reconstruct the... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00353/46422/46151.pdf |
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