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Schoon P.L.,Netherlands Institute for Sea Research | Heilmann-Clausen C.,University of Aarhus | Schultz B.P.,MUSERUM | Sinninghe Damste J.S.,Netherlands Institute for Sea Research | Schouten S.,Netherlands Institute for Sea Research
Organic Geochemistry | Year: 2015

Analysis of sediments deposited at different latitudes around the world during the Palaeocene-Eocene Thermal Maximum (PETM; ~56Ma) have revealed a globally profound warming phase, regionally varying from 5-8°C. Such records from Europe have not yet been obtained. We studied the variations in sea surface and continental mean annual air temperatures (SST and MAT, respectively) and the distribution patterns and stable carbon isotopes of higher plant derived n-alkanes in two proximal PETM sections (Fur and Store Bælt, Denmark) from the epicontinental North Sea Basin. A negative carbon isotope excursion (CIE) of 4-7‰ was recorded in land plant derived n-alkanes, similar to what has been observed for other PETM sections. However, differences observed between the two proximal sites suggest that local factors, such as regional vegetation and precipitation patterns, also influenced the CIE. The presence of S-bound isorenieratene derivatives at the onset of the PETM and increased organic carbon contents points to a rapid shift in depositional environment; from well oxygenated to anoxic and sulfidic. These euxinic conditions are comparable with those during the PETM in the Arctic Ocean. SSTs inferred from TEX86 show relatively low temperatures followed by an increase of ~7°C across the PETM. At the Fur section, a remarkably similar temperature record was obtained for MAT using the MBT'/CBT proxy. However, the MAT record of the Store Bælt section did not reveal this warming. © 2014 Elsevier Ltd. Source

Crouch E.M.,Institute of Geological & Nuclear Sciences | Willumsen P.S.,MUSERUM | Willumsen P.S.,University of Aarhus | Kulhanek D.K.,Institute of Geological & Nuclear Sciences | And 2 more authors.
Review of Palaeobotany and Palynology | Year: 2014

Organic-walled dinoflagellate cyst (dinocyst) assemblages are documented from Paleocene (New Zealand Teurian Stage) sediments in five sections from eastern New Zealand: Tawanui, Angora Road and Toi Flat-1 core in the East Coast Basin, mid-Waipara River in the Canterbury Basin, and ODP Site 1121 on the eastern margin of Campbell Plateau. Based on dinocyst results from these sections, along with published earliest Paleocene records from the East Coast, Canterbury and Great South Basins, a revised Paleocene (Teurian) dinocyst zonation is proposed. The zones are labelled as NZDP - New Zealand Dinocyst Paleocene - and are all interval zones. The eight zones, NZDP1 to NZDP8, encompass the entire Paleocene, from the Cretaceous-Paleogene boundary at 66.04. Ma to the Paleocene-Eocene boundary at 55.96. Ma. Correlation of the NZDP zones with the International and New Zealand Time Scales is provided, and is primarily based on correlation with calcareous nannofossil biostratigraphy. Three new dinocyst species are described: Leptodinium? pustulatum sp. nov., Cerodinium angulatum sp. nov., and Vozzhennikovia tawanuiensis sp. nov. © 2014 Elsevier B.V. Source

Lindgren J.,Lund University | Moyer A.,North Carolina State University | Schweitzer M.H.,Lund University | Schweitzer M.H.,North Carolina State University | And 8 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2015

Colour, derived primarily from melanin and/or carotenoid pigments, is integral to many aspects of behaviour in living vertebrates, including social signalling, sexual display and crypsis. Thus, identifying biochromes in extinct animals can shed light on the acquisition and evolution of these biological traits. Both eumelanin and melanin-containing cellular organelles (melanosomes) are preserved in fossils, but recognizing traces of ancient melanin-based coloration is fraught with interpretative ambiguity, especially when observations are based on morphological evidence alone. Assigning microbodies (or, more often reported, their ‘mouldic impressions’) as melanosome traces without adequately excluding a bacterial origin is also problematic because microbes are pervasive and intimately involved in organismal degradation. Additionally, some forms synthesize melanin. In this review, we survey both vertebrate and microbial melanization, and explore the conflicts influencing assessment of microbodies preserved in association with ancient animal soft tissues.We discuss the types of data used to interpret fossil melanosomes and evaluate whether these are sufficient for definitive diagnosis. Finally, we outline an integrated morphological and geochemical approach for detecting endogenous pigment remains and associated microstructures in multimillion-year-old fossils. © 2015 The Author(s). Source

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