Reitner, Joachim

[["dc.bibliographiccitation.firstpage","653"],["dc.bibliographiccitation.journal","Palaeogeography, Palaeoclimatology, Palaeoecology"],["dc.bibliographiccitation.lastpage","672"],["dc.bibliographiccitation.volume","490"],["dc.contributor.author","Friesenbichler, Evelyn"],["dc.contributor.author","Richoz, Sylvain"],["dc.contributor.author","Baud, Aymon"],["dc.contributor.author","Krystyn, Leopold"],["dc.contributor.author","Sahakyan, Lilit"],["dc.contributor.author","Vardanyan, Sargis"],["dc.contributor.author","Peckmann, Jörn"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Heindel, Katrin"],["dc.date.accessioned","2019-07-22T14:17:09Z"],["dc.date.available","2019-07-22T14:17:09Z"],["dc.date.issued","2018"],["dc.description.abstract","The end-Permian mass extinction was the most severe biotic crisis in Earth's history. In its direct aftermath microbial communities colonized some of the space left vacant after the severe decline of skeletal metazoans. The Permian-Triassic boundary microbialites were peculiarly abundant on low-latitude shallow-marine carbonate shelves of central Tethyan continents. Armenia features particularly well preserved and diverse basal Triassic sponge-microbial build-ups (BTSMBs), which were not studied in detail to date. Here, the Chanakhchi section in southern Armenia is described petrographically and by means of stable isotope analyses. The Armenian BTSMBs formed in a distally open marine setting on a pelagic carbonate ramp in the course of two phases of microbial growth during the Induan (Lower Triassic). The BTSMBs are represented by predominantly thrombolitic but also dendrolitic and digitate stromatolite biostromes and mounds that vary in height between 5 cm to 12 m. The digitate stromatolites are associated with calcium carbonate crystal fans (CCFs). Microfacies analyses revealed that the BTSMBs exhibit a number of different growth forms and internal fabrics. The formation of CCFs was apparently not devoid of biological influence and took place above the sediment surface. The abundance of sponges in the BTSMBs reveals that ecologically complex metazoan-microbial reefs have been present already early after the end-Permian mass extinction. However, the formation of biostromes and mounds did not depend on sponges or other metazoans. BTSMBs that formed during the second microbial growth phase revealed similar δ13C-values like the surrounding sediment. In contrast, the δ13Cmicrobialite and δ13Csediment values from the BTSMBs and CCFs of the first growth phase show a difference of up to + 2.3‰, suggesting a significant influence of photoautotrophy during microbially induced carbonate precipitation."],["dc.identifier.doi","10.1016/j.palaeo.2017.11.056"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61825"],["dc.language.iso","en"],["dc.relation.issn","0031-0182"],["dc.title","Sponge-microbial build-ups from the lowermost Triassic Chanakhchi section in southern Armenia: Microfacies and stable carbon isotopes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1348"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Life"],["dc.bibliographiccitation.volume","12"],["dc.contributor.affiliation","Luo, Cui; 1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China"],["dc.contributor.affiliation","Pei, Yu; 2Department of Geosciences, University of Tübingen, 72076 Tübingen, Germany"],["dc.contributor.affiliation","Richoz, Sylvain; 3Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden"],["dc.contributor.affiliation","Li, Qijian; 1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China"],["dc.contributor.affiliation","Reitner, Joachim; 4Department of Geobiology, Centre of Geosciences, University of Göttingen, Goldschmidtstraße 3, 37073 Göttingen, Germany"],["dc.contributor.author","Luo, Cui"],["dc.contributor.author","Pei, Yu"],["dc.contributor.author","Richoz, Sylvain"],["dc.contributor.author","Li, Qijian"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.editor","Bianucci, Giovanni"],["dc.date.accessioned","2022-10-04T10:21:05Z"],["dc.date.available","2022-10-04T10:21:05Z"],["dc.date.issued","2022"],["dc.date.updated","2022-11-11T13:14:41Z"],["dc.description.abstract","Structures similar to fossilized nonspicular demosponges have been reported in carbonates throughout the Phanerozoic and recently in rocks dating back to 890 Ma ago. Interpretation of these records is increasingly influential to our understanding of metazoans in multiple aspects, including their early evolution, the ecology in fossil reefs, and recovery after mass extinction events. Here, we propose six identification criteria of “Keratosa”-type nonspicular demosponge fossils based on the well-established taphonomical models and their biological characteristics. Besides, sponge fossils of this kind from the lowermost Triassic of Chanakhchi (Armenia) are described with a 3-D reconstruction to exemplify the application of these criteria in recognition of such organisms. Subsequently, the state-of-the-art understanding of the taxonomy and evolution of these fossil sponges, a previously poorly addressed topic, is summarized. The morphology of the Triassic Chanakhchi fossils indicates an affinity with verongimorphs, a group that may have evolved by Cambrian Age 3. Other than that, further efforts are encouraged to forge quantitative criteria based on the here proposed descriptive version and to explore the taxonomic diversity and evolutionary details of these fossil nonspicular demosponges."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2022"],["dc.identifier.doi","10.3390/life12091348"],["dc.identifier.pii","life12091348"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/114326"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-600"],["dc.publisher","MDPI"],["dc.relation.eissn","2075-1729"],["dc.rights","CC BY 4.0"],["dc.title","Identification and Current Palaeobiological Understanding of “Keratosa”-Type Nonspicular Demosponge Fossils in Carbonates: With a New Example from the Lowermost Triassic, Armenia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","187"],["dc.bibliographiccitation.journal","Gondwana Research"],["dc.bibliographiccitation.lastpage","202"],["dc.bibliographiccitation.volume","61"],["dc.contributor.author","Heindel, Katrin"],["dc.contributor.author","Foster, William J."],["dc.contributor.author","Richoz, Sylvain"],["dc.contributor.author","Birgel, Daniel"],["dc.contributor.author","Roden, Vanessa Julie"],["dc.contributor.author","Baud, Aymon"],["dc.contributor.author","Brandner, Rainer"],["dc.contributor.author","Krystyn, Leopold"],["dc.contributor.author","Mohtat, Tayebeh"],["dc.contributor.author","Koşun, Erdal"],["dc.contributor.author","Twitchett, Richard J."],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Peckmann, Jörn"],["dc.date.accessioned","2019-07-22T14:10:46Z"],["dc.date.available","2019-07-22T14:10:46Z"],["dc.date.issued","2018"],["dc.description.abstract","After the latest Permian mass extinction event, microbial mats filled the ecological niche previously occupied by metazoan reefs, resulting in widespread microbialites. This study focuses on the lipid biomarker (molecular fossil) and invertebrate fossil records from Neotethyan platform margin sections to understand microbial-metazoan bioherm formation. Here, we find that early Griesbachian thrombolitic and stromatolitic microbialites from Çürük Dag (Turkey) and Kuh e Surmeh (Iran) contain abundant lipid biomarkers (molecular fossils), representing input from cyanobacteria, anoxygenic phototrophic bacteria, sulfate-reducing bacteria, and halophilic archaea. The biomarker inventory suggests that the microbialites were constructed by cyanobacteria-dominated microbial mats. Biomarkers of halophilic archaea are interpreted to reflect input from the water column, suggesting that the Neotethys experienced at least episodically hypersaline conditions. We also demonstrate that bacteria, possible keratose sponges (up to 50% of the carbonate is represented by the possible sponges), and microconchids lived synergistically to form microbial-metazoan bioherms in the immediate aftermath of the extinction along the western margin of the Neotethys. Abundant fossils of oxygen-dependent invertebrates (i.e. microconchids, bivalves, gastropods, brachiopods, and ostracods) and foraminifers were also found within these bioherms. The presence of invertebrates in conjunction with abundant molecular fossils of cyanobacteria indicates an oxygenated water column. Even though the presence of the biomarker isorenieratane in microbialites may considered as evidence for euxinic conditions in the water column, its absence in the background sediments rather points to a source organism belonging to the mat community. The new finding of bioherms built in part by metazoans suggests that reef ecosystems underwent a major turnover across the extinction event, and shortens the ‘metazoan reef gap’ to just the uppermost Changhsingian. During the Early Triassic, therefore, reefal ecosystems were able to recover in oxygenated settings since the earliest Griesbachian, albeit in an impoverished state."],["dc.identifier.doi","10.1016/j.gr.2018.05.007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61821"],["dc.language.iso","en"],["dc.relation.issn","1342-937X"],["dc.title","The formation of microbial-metazoan bioherms and biostromes following the latest Permian mass extinction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]