Joachim Reitner

Joachim Reitner
Georg-August-Universität Göttingen | GAUG · Department of Geobiology

Prof. Dr.

About

473
Publications
123,605
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
13,036
Citations

Publications

Publications (473)
Preprint
Full-text available
Fossilised fibrous skeletons of non-spicular demosponges have been reported in carbonates throughout the Phanerozoic and recently from rocks dated back to 890 Ma ago. These records expanded our understanding of metazoans in multiple aspects, including their early evolution, the cryptic ecology in fossil reefs, and recovery after mass extinction eve...
Article
Full-text available
Sponge fossils from the Cambrian black shales have attracted attention from both palaeontologists and geochemists for many years in terms of their high diversity, beautiful preservation and perplexing adaptation to inhospitable living environments. However, the body shape of these sponges, which contributes to deciphering adaptive evolution, has no...
Article
Full-text available
Sponge fossils from the Cambrian black shales have attracted attention from both palaeontologists and geochemists for many years in terms of their high diversity, beautiful preservation and perplexing adaptation to inhospitable living environments. However, the body shape of these sponges, which contributes to deciphering adaptive evolution, has no...
Article
Full-text available
Following the end-Permian crisis, microbialites were ubiquitous worldwide. For instance, Triassic deposits in the Germanic Basin provide a rich record of stromatolites as well as of microbe-metazoan build-ups with nonspicular demosponges. Despite their palaeoecological significance, however, all of these microbialites have only rarely been studied....
Article
Full-text available
Microbial mats represented the earliest complex ecosystems on Earth, since fossil mineralized examples (i.e., microbialites) date back to the Archean Eon. Some microbialites contain putative remains of organic matter (OM), however the processes and pathways that lead to the preservation of OM within microbialite minerals are still poorly understood...
Article
The new hexactinellid stiodermatid Turgidaspongia porosa gen. et sp. nov. is described from the Ordovician-Silurian boundary sequence in Beigong of Jingxian County, south Anhui Province, China. The spherical, thin-walled species possessed unique features including unusually large parietal gaps on the body wall, swollen hexactines as hypodermalia, a...
Article
Full-text available
Dynamic sedimentary processes are a key parameter for establishing the habitability of planetary surface environments on Earth and beyond and thus critical for reconstructing the early evolution of life on our planet. This paper presents a sedimentary section from the ca 3.48 Ga Dresser Formation (Pilbara Craton, Western Australia) that contains hi...
Article
Full-text available
The embryo-like fossils from the early Ediacaran Weng'an Biota (Southwest China, 609 million years ago), widely interpreted as members of holozoans, potentially provide insights to understanding the early evolution of development of metazoans and the rise of the animal kingdom. However, the biodiversity of the embryo-like fossil assemblage is large...
Article
Full-text available
Extensive beds of the deep-sea mussel Bathymodiolus mauritanicus (currently also known as Gigantidas mauritanicus ) linked to active cold seeps related to fissure-like activity on Al Gacel mud volcano, Gulf of Cádiz, were filmed and sampled for the first time during the oceanographic expedition SUBVENT-2 aboard R/V Sarmiento de Gamboa. Al Gacel mud...
Article
Full-text available
Ooids (subspherical particles with a laminated cortex growing around a nucleus) are ubiquitous in the geological record since the Archean and have been widely studied for more than two centuries. However, various questions about them remain open, particularly about the role of microbial communities and organic matter in their formation and developm...
Article
Full-text available
Geological evidence suggests liquid water near the Earth’s surface as early as 4.4 gigayears ago when the faint young Sun only radiated about 70% of its modern power output. At this point, the Earth should have been a global snowball if it possessed atmospheric properties similar to those of the modern Earth. An extreme atmospheric greenhouse effec...
Article
Full-text available
Fossils within early Cambrian phosphorites worldwide are often well preserved due to early diagenetic permineralization. Here, we examine the fossil record contained within phosphorites of the Lower Cambrian Pusa Formation (late Fortunian to Cambrian Stage 2) in Fontanarejo, central Spain. The sedimentology and age of these phosphorites have been c...
Article
Full-text available
A massive occurrence of microbial carbonates, including abundant sponge remains, within the Devonian Elbingerode Reef Complex was likely deposited in a former cavity of the fore-reef slope during the early Frasnian. It is suggested that the formation of microbial carbonate was to a large part favored by the activity of heterotrophic, i.e., sulfate-...
Preprint
Full-text available
The aftermath of the Permian – Triassic crisis is characterized by ubiquitous occurrences of microbial sediments around the world. For instance, Triassic deposits of the Germanic Basin have shown to provide a rich record of stromatolites as well as of microbe-metazoan build-ups with non-spicular demosponges. Despite their paleoecological significan...
Article
Full-text available
The so‐called Permian–Triassic mass extinction was followed by a prolonged period of ecological recovery that lasted until the Middle Triassic. Triassic stromatolites from the Germanic Basin seem to be an important part of the puzzle but have barely been investigated so far. Here, we analysed late Anisian (upper Middle Muschelkalk) stromatolites fr...
Article
Archaeocyaths were one of the major animal groups contributing to the Cambrian Explosion. Despite an overall poriferan appearance of their hypercalcified skeletons, they exhibit a number of peculiar features such as the presence of septa and an absence of spicules. This sets archaeocyaths apart from general trends in early poriferan evolution. Foss...
Preprint
Full-text available
Although ooids typically occur rolling around in agitated waters, here we describe for the first time aragonite ooids forming statically within microbial mats from hypersaline ponds of Kiritimati (Kiribati, central Pacific). Their formation processes are discussed and interprted as product of mat evolution, through a combination of organic and envi...
Article
Full-text available
Abstract The study of hydrothermal travertines contributes to the understanding of the interaction between physico‐chemical processes and microbial mats in carbonate precipitation. Three active travertine sites were investigated in Central Italy to characterise the types of carbonate precipitates and the associated microbial mats at varying physico...
Preprint
Full-text available
The so-called Permian — Triassic mass extinction was followed by a prolonged period of ecological recovery that lasted until the Middle Triassic. Triassic stromatolites from the Germanic Basin seem to be an important part of the puzzle, but have barely been investigated so far. Here we analyzed late Anisian (upper Middle Muschelkalk) stromatolites...
Article
Full-text available
It is widely hypothesised that primeval life utilised small organic molecules as sources of carbon and energy. However, the presence of such primordial ingredients in early Earth habitats has not yet been demonstrated. Here we report the existence of indigenous organic molecules and gases in primary fluid inclusions in c. 3.5-billion-year-old barit...
Article
Full-text available
(1) Background: Microbial communities in terrestrial, calcifying high-alkaline springs are not well understood. In this study, we investigate the structure and composition of microbial mats in ultrabasic (pH 10–12) serpentinite springs of the Voltri Massif (Italy). (2) Methods: Along with analysis of chemical and mineralogical parameters, environme...
Preprint
Full-text available
Fossils within early Cambrian phosphorites worldwide are often well preserved due to early diagenetic permineralization. Here, we examine the fossil record contained within phosphorites of the Lower Cambrian Pusa Formation (late Fortunian to Cambrian Stage 2) in Fontanarejo, central Spain. The sedimentology and age of these phosphorites have been c...
Article
Full-text available
The Permian–Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian–Triassic Critical Interval (P–TrCI) in the Xiakou area (South China). Six microfacies (MF) were class...
Article
Hydrothermal iron (Fe)-rich sediments were recovered from the Tagoro underwater volcano (Central Atlantic) that was built during the 2011–2012 volcanic event. Cruises in 2012 and 2014 enabled the monitoring and sampling of the early-stage establishment of a hydrothermal system. Degassing vents produced acoustic flares imaged on echo-sounders in Jun...
Article
Full-text available
The Permian–Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian–Triassic Critical Interval (P–TrCI) in the Xiakou area (South China). Six microfacies (MF) were class...
Article
Full-text available
We sequenced the metagenome of an anoxygenic photosynthetic consortium originating from pond water and reconstructed four metagenome-assembled genomes. These genomes include Desulfocapsa, Paludibacter, Lamprocystis, and Rhodocyclaceae representatives and indicate the presence of genes for dissimilatory sulfate reduction and oxidation of reduced sul...
Article
The definition of a fossil ecological community from fossil associations has always been problematic. Determining coevality of the members of a fossil association has posed one of the most ravelling problems in this matter. However, in case of relicts of fossil reefs, this problem seems, to some extent, solvable due to the frequency of fossil findi...
Preprint
Full-text available
The Permian-Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian-Triassic Critical Interval (P-TrCI) in the Xiakou area (South China). Six microfacies (MF) were class...
Article
It has long been recognized that the stable oxygen isotope ¹⁸O/¹⁶O ratios of chemical sediments show a systematic decrease with increasing age. This continuous, 3.8 Ga long secular trend has been attributed to 80 °C hot early Earth oceans, a ~15‰ lower ¹⁸O/¹⁶O ratio of Archean seawater, or diagenetic obliteration of the original isotope signal. We...
Preprint
Full-text available
The study of hydrothermal travertines contributes to the understanding of the interaction between physico-chemical processes and the role played by microbial mats and biofilms in influencing carbonate precipitation. Three active travertine sites were investigated in Central Italy to identify the types of carbonate precipitates and the associated mi...
Preprint
Full-text available
Geological evidence suggests liquid water near the Earth's surface as early as 4.4 gigayears ago when the faint young Sun only radiated about 70 % of its modern power output. At this point, the Earth should have been a global snowball. An extreme atmospheric greenhouse effect, an initially more massive Sun, release of heat acquired during the accre...
Article
Carbonates and cherts in the 3.35 billion-year-old Strelley Pool Formation (Fm.; Australia) host stromatolites that are among the oldest remnants of life on Earth. However, it is still not entirely clear whether these mineral phases are authigenic precipitates, and whether they represent reliable geochemical archives of early Earth environments. He...
Article
Full-text available
Siboglinids were sampled from four mud volcanoes in the Gulf of Cádiz (El Cid MV, Bonjardim MV, Al Gacel MV, and Anastasya MV). These invertebrates are characteristic to cold seeps and are known to host chemosynthetic endosymbionts in a dedicated trophosome organ. However, little is known about their tube as a potential niche for other microorganis...
Article
Full-text available
Microbial mats are self-sustaining benthic ecosystems composed of highly diverse microbial communities. It has been proposed that microbial mats were widespread in Proterozoic marine environments, prior to the emergence of bioturbating organisms at the Precambrian–Cambrian transition. One characteristic feature of Precambrian biomarker records is t...
Conference Paper
The 3.42 Ga Buck Reef Chert (Barberton Greenstone Belt, South Africa) provides a rare sequence of exceptionally well preserved silicified microbial mats, containing abundant kerogen. We investigated this macromolecular organic material (cherts from drill cores, Barberton Drilling Project - Peering into the Cradle of Life) on structural (microscopy,...
Article
Full-text available
Organic-rich laminated shales and limestones from the Monte San Giorgio (Lugano Prealps, Switzerland) are known as famous fossil lagerstätten for excellently preserved fossils from the Middle Triassic Period. The various bituminous shales from Monte San Giorgio are thermally immature and rich in diverse organic compounds, which provide unique subst...
Article
Full-text available
Organic matter in Archean hydrothermal cherts may provide an important archive for molecular traces of the earliest life on Earth. The geobiological interpretation of this archive, however, requires a sound understanding of organic matter preservation and alteration in hydrothermal systems. Here we report on organic matter (including molecular bios...
Article
Rossellids are geographically widespread in the modern deep-water sponge community. They are referred to Lyssacinosida, characterized by hypodermal pentactines and choanosomal megascleres of hexactines and diactines or the latter only. The fossil records of rossellids are usually found in the Cenozoic, with the earliest existence known from the Upp...
Preprint
Full-text available
Siboglinid worms were sampled from four mud volcanoes in the Gulf of Cádiz (El Cid MV, Bonjardim MV, Al Gacel MV and Anastasya MV). These invertebrates are characteristic to cold seeps and are known to host chemosynthetic endosymbionts in a dedicated trophosome organ. However, little is known about their tube as a potential niche for other chemosyn...
Preprint
Siboglinid worms were sampled from four mud volcanoes in the Gulf of Cádiz (El Cid MV, Bonjardim MV, Al Gacel MV and Anastasya MV). These invertebrates are characteristic to cold seeps and are known to host chemosynthetic endosymbionts in a dedicated trophosome organ. However, little is known about their tube as a potential niche for other chemosyn...
Preprint
Full-text available
Microbial mats are self-sustaining benthic ecosystems composed of highly diverse microbial communities. It has been proposed that microbial mats were widespread in Proterozoic marine environments, prior to the emergence of bioturbating organisms at the Precambrian-Cambrian transition. One characteristic feature of Precambrian biomarker records is t...
Article
Full-text available
Azooxanthellate cold-water corals (CWCs) have a global distribution and have commonly been found in areas of active fluid seepage. The relationship between the CWCs and these fluids, however, is not well understood. This study aims to unravel the relationship between CWC development and hydrocarbon-rich seepage in Pompeia Province (Gulf of Cádiz, A...
Poster
Well preserved early Archean sedimentary successions are rare and usually consist of chemical sediments (e.g. cherts) and few volcanoclastic rocks. Furthermore, reworked Archean material is extremely scarce due to only small continental islands and weakly developed shelf areas. However, a 5 – 6 m thick and c. 100 m long channel fill within the 3.5...
Article
Three-dimensionally, in situ preserved sponge fossils were collected from the phosphorites at the basal Niutitang Formation (Cambrian Stage 2) in Hunan Province, China. These fossils are preserved as nodular bodies in authigenic carbonaceous cherty Ca-phosphorites. Spicules are either completely embedded in cryptocrystalline phosphate or immediatel...
Article
Full-text available
In this paper we describe four new fossil associations of “reef” and “reef”-like environments of the St. Cassian Formation (Ladinian-Carnian, Dolomites, NE Italy), based on thirty thin sections from 10 “Cipit boulders” olistoliths, which slided from the Cassian platform into coeval basin sediments. The fossil associations were determined by means o...
Article
Full-text available
Organic matter in Archean hydrothermal cherts may provide an important archive for molecular traces of earliest life on Earth. The geobiological interpretation of this archive, however, requires a sound understanding of organic matter preservation and alteration in hydrothermal systems. Here we report on organic matter (including molecular biosigna...
Article
The ecological relationships among six microencruster species from the Cipit boulders of the St Cassian Formation (Ladinian–Carnian of the Dolomites, NE Italy) were studied in detail. 112 thin sections in postcard format (10 × 15 cm) and in 7.5 × 10 cm from the localities Alpe di Specie and Misurina were taken into account. Initially, twelve microe...
Chapter
Objects collected over more than 300 years, and nearly 250 years of museum tradition have led to one of today’s largest palaeontological collections in Germany. About 2.5 million palaeontological objects are kept in the collections of the Geoscience Museum of the Georg August University, among them types and original material regarding several thou...
Preprint
Full-text available
Azooxanthellate cold-water corals (CWCs) are globally widespread and have commonly been found in areas of active fluid seepage. The relationship between the CWCs and these fluids, however, is not well understood. This study aims at unravelling the relationship between CWC development and hydrocarbon-rich seepage in the Pompeia Province (Gulf of Cád...
Article
This study records the first occurrence of a lower Cambrian archaeocyathan fauna in limestone cobbles from Carboniferous glacigenic deposits of the Dwyka Group of the Aranos Basin in Namibia. Petrographic and microfacies analysis of 17 large, middle and standard thin sections reveals two distinctive limestone cobble facies: (a) bioclastic wackeston...
Article
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 format...
Article
Eukaryotic steranes are typically absent or occur in very low concentrations in Precambrian sedimentary rocks. However, it is as yet unclear whether this may reflect low source inputs or a preservational bias. For instance, it has been proposed that eukaryotic lipids were profoundly degraded in benthic microbial mats that were ubiquitous prior to t...
Article
Available under: https://onlinelibrary.wiley.com/doi/10.1111/gbi.12284 Fossil derivatives of isorenieratene, an accessory pigment in brown‐colored green sulfur bacteria, are often used as tracers for photic zone anoxia through Earth's history, but their diagenetic behavior is still incompletely understood. Here, we assess the preservation of isor...
Article
Full-text available
Archaean hydrothermal chert veins commonly contain abundant organic carbon of uncertain origin (abiotic vs. biotic). In this study, we analysed kerogen contained in a hydrothermal chert vein from the ca. 3.5 Ga Dresser Formation (Pilbara Craton, Western Australia). Catalytic hydropyrolysis (HyPy) of this kerogen yielded n-alkanes up to n-C22, with...
Article
Full-text available
We describe four new fossil associations obtained from nine allochthonous blocks—the so-called Cipit boulders—on the basis of 23 thin sections. The samples were collected from the well-known Middle–Late Triassic St. Cassian Formation (NE Italy). These associations were determined by considering all biomorpha and microbialitic structures that were q...
Article
Archaean hydrothermal chert veins commonly contain abundant organic carbon of uncertain origin (abiotic vs. biotic). In this study, we analysed kerogen contained in a hydrothermal chert vein from the ca. 3.5 Ga old Dresser Formation (Pilbara Craton, Western Australia). Catalytic hydropyrolysis (HyPy) of this kerogen yielded n-alkanes up to n-C22, w...