Dieter Korn | Museum für Naturkunde Berlin (original) (raw)

Dieter Korn

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Papers by Dieter Korn

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Gondwana Research, 2014

ABSTRACT The end-Permian mass extinction has been associated with severe global warming. Main sta... more ABSTRACT The end-Permian mass extinction has been associated with severe global warming. Main stage volcanism of the Siberian Traps occurred at or near the extinction interval and has been proposed as a likely greenhouse catalyst. In this study, a high-resolution δ18O record is established using diagenetically resistant apatite of conodonts and low-Mg calcite of brachiopods from stratigraphically well-constrained Permian-Triassic (P-Tr) boundary successions in northwestern Iran. A new evaluation is made for previously published conodont δ18O values from South China and revised palaeotemperatures are presented together with new data from Wuchiapingian to Griesbachian sections in Iran. δ18O data from P-Tr sections in Iran document tropical sea surface temperatures (SST) of 27-33 °C during the Changhsingian with a negative shift in δ18O starting at the extinction horizon, translating into a warming of SSTs to over 35 °C. The results are consistent with re-calculated SSTs of the South Chinese sections. Warming was associated with an enhanced hydrological cycle involving increased tropical precipitation and monsoonal activity in the Tethys Sea. Global warming, intensification of the hydrological cycle and associated processes, vertical water column stratification, eutrophication and subsequent local anoxia may all have facilitated an extinction event.

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www.foss-rec.net/18/57/2015/ doi:10.5194/fr-18-57-2015 © Author(s) 2015. CC Attribution 3.0 Licen... more www.foss-rec.net/18/57/2015/ doi:10.5194/fr-18-57-2015 © Author(s) 2015. CC Attribution 3.0 License. Facies, origin, and palaeontological inventory of an Early Carboniferous neptunian dyke in the Devonian reef limestone

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PalZ, 2021

The Protocanites Beds of the Black Forest Massif (Germany) form an important lithostratigraphic k... more The Protocanites Beds of the Black Forest Massif (Germany) form an important lithostratigraphic key bed, as the index fossils contained in this formation enable correlation within large areas of the internal zone of the central Variscan Belt of Europe. Furthermore, the formation provides significant information on the geodynamic evolution of the Moldanubian Zone. The stratigraphic age of the formation has been a subject of controversy in the past; a Devonian to Viséan age has been proposed. To determine the age of the Protocanites Beds, two ammonoid specimens from the Protocanites Beds of Schönau are re-described here. They belong to Becanites abnobensis and Pericylcus princeps and fix the stratigraphic position of the Protocanites Beds to the early Late Tournaisian.

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Fossil Imprint, 2019

In the latest Famennian, black shale deposition occurred in many regions, some suggested a marine... more In the latest Famennian, black shale deposition occurred in many regions, some suggested a marine transgression as the explanation while others saw a link with higher organic input from the land. In either case, the Hangenberg Black Shale was most likely deposited under low oxygen conditions, which enabled exceptional fossil preservation in some regions such as the southern Maïder Basin of Morocco. Here, we provide the first account of small circular structures, in some cases with thin carbon films, which remained on ammonoid and bactritoid conchs. Due to similarities in their morphology and size with other occurrences documented from Europe, we propose that these structures may represent gastropod eggs. We also discuss whether egg-deposition occurred in the water column or on the sediment surface.

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Bulletin of Geosciences, 2017

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Fossil Record, 2018

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PloS one, 2016

The Ammonoidea is a group of extinct cephalopods ideal to study evolution through deep time. The ... more The Ammonoidea is a group of extinct cephalopods ideal to study evolution through deep time. The evolution of the planispiral shell and complexly folded septa in ammonoids has been thought to have increased the functional surface area of the chambers permitting enhanced metabolic functions such as: chamber emptying, rate of mineralization and increased growth rates throughout ontogeny. Using nano-computed tomography and synchrotron radiation based micro-computed tomography, we present the first study of ontogenetic changes in surface area to volume ratios in the phragmocone chambers of several phylogenetically distant ammonoids and extant cephalopods. Contrary to the initial hypothesis, ammonoids do not possess a persistently high relative chamber surface area. Instead, the functional surface area of the chambers is higher in earliest ontogeny when compared to Spirula spirula. The higher the functional surface area the quicker the potential emptying rate of the chamber; quicker cham...

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