Article
Paleontology
Marcelo G. Carrera, Gustavo G. Voldman, Matias J. Mango, Galina P. Nestell
Summary: The study describes the unusual findings of tiny sclerite-type elements from the Lower and Middle Ordovician in the San Juan Formation of the Argentine Precordillera, which may represent the oldest occurrence of skeletal elements in the evolutionary history of octocorals. The morphologic characteristics of these elements are similar to those found in alcyonacean octocorals, and their affinities with sponge spicules are also discussed. The discovery of a new genus Catenatus and a new species Catenatus argentinus is also reported.
ACTA PALAEONTOLOGICA POLONICA
(2021)
Article
Geosciences, Multidisciplinary
Clara Eugenia Cisterna, Beatriz Coira
Summary: The Suri-Las Planchadas Volcanic-Sedimentary Complex in the northwest of the Sierras Pampeanas is a succession of Early to Middle Ordovician volcanic and sedimentary rocks. It includes various types of volcanic lithofacies and volcaniclastic deposits, representing the evolution of volcanic activity.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2022)
Article
Geography, Physical
Thomas Servais, Borja Cascales-Minana, David A. T. Harper, Bertrand Lefebvre, Axel Munnecke, Wenhui Wang, Yuandong Zhang
Summary: During the late Precambrian and early Cambrian, there was a gradual increase in the diversity of life, with the appearance of almost all animal phyla. However, there is no clear Cambrian explosion and Ordovician event, but rather a continuous and complex radiation of life throughout the Ordovician.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Multidisciplinary Sciences
Farid Saleh, Pauline Guenser, Corentin Gibert, Diego Balseiro, Fernanda Serra, Beatriz G. Waisfeld, Jonathan B. Antcliffe, Allison C. Daley, M. Gabriela Mangano, Luis A. Buatois, Xiaoya Ma, Daniel Vizcaino, Bertrand Lefebvre
Summary: This study investigates the assembly processes of Early Ordovician trilobite and echinoderm communities and finds that dispersal increased over time in trilobite communities but not in echinoderms. Dispersal was likely triggered by factors such as the planktic revolution, fall in seawater temperatures, and changes in oceanic circulation, with control from tectonic frameworks and phylogenetic constraints. The diachronous increase in dispersal within trilobite communities highlights the complexity of ecosystem structuring during the early stages of the Ordovician Radiation.
SCIENTIFIC REPORTS
(2022)
Article
Paleontology
Aram Bayet-Goll, Alfred Uchman, Mehdi Daraei, Carlos Neto de Carvalho
Summary: The abundant occurrence of Trichophycus venosus trace fossils in the Tremadocian-to-Floian siliciclastic deposits in central Iran indicates an increase in exploitation of offshore infaunal ecospace, which negatively affects the preservation of shallow-tier trace fossils, particularly those produced by trilobites. The development of the Crowded Trichophycus ichnofabric (CTI) suggests stable habitats with high food and oxygen content in muddy substrates above the storm wave base. The ethology and morphology of Trichophycus point to a combined dwelling-feeding activity of the resident producer, indicating an infaunalization related to the Great Ordovician Biodiversification Event.
Article
Paleontology
Fernando J. Lavie, Ana I. Mestre, Marcelo G. Carrera
Summary: New linguliform microbrachiopods from the Middle Ordovician were described and illustrated in this study, recovered from the uppermost beds of the San Juan Formation in Argentina. This low-diversity lingulate association displayed close similarities with coeval faunas in other regions.
JOURNAL OF PALEONTOLOGY
(2021)
Article
Geography, Physical
Sara B. Pruss, Lucy Helms, Emma Roth
Summary: This study examines the Late Ordovician coral reefs of the Lourdes Formation in western Newfoundland. It reveals that reef environments have higher skeletal abundance than adjacent settings, and the abundance of skeletal animals is influenced by specific environmental conditions such as supersaturation of CaCO3, wave activity, and warm temperatures. This highlights the importance of reefs as suitable habitats for skeletal organisms during the Early Paleozoic.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Multidisciplinary Sciences
Farid Saleh, Romain Vaucher, Muriel Vidal, Khadija El Hariri, Lukas Laibl, Allison C. Daley, Juan Carlos Gutierrez-Marco, Yves Candela, David A. T. Harper, Javier Ortega-Hernandez, Xiaoya Ma, Ariba Rida, Daniel Vizcaino, Bertrand Lefebvre
Summary: The Fezouata Biota is a unique Early Ordovician fossil assemblage that revolutionized our understanding of Earth's early animal diversification. The new fossil locality Taichoute extends the temporal distribution of fossil preservation and expands the range of depositional environments. The discovery at this site provides important insights during a key evolutionary transition in the history of life on Earth.
SCIENTIFIC REPORTS
(2022)
Article
Geography, Physical
Ruo-ying Fan, Rui-wen Zong, Yi-ming Gong
Summary: Trace fossils provide unique evidence of the body plan and behavioral complexity of animals, with a diverse ichnoassemblage discovered from deep-marine deposits in Inner Mongolia, North China during the Middle-Upper Ordovician period. The complex trace fossils suggest distinct behavioral complication and novelty in deep-sea communities during this time, possibly reflecting an evolution towards more delicate, geometric, and efficient feeding patterns. The Late Ordovician period may represent a peak in ichnodiversity and behavioral complexity of deep-sea ichnofauna, reflecting the complex interplay of biodiversity, biomass, and ecological changes during this time.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geology
Fernando E. Lopez, Gladys Ortega, Guillermo L. Albanesi, Aldo L. Banchig
Summary: Upper Ordovician graptolites and conodonts from the Yerba Loca Formation in Argentina provide important regional and global correlations, particularly in poorly known deep marine environments. The fossils collected include late Sandbian Climacograptus bicornis Zone graptolites and Amorphognathus tvaerensis Zone conodonts. The presence of early Sandbian Nemagraptus gracilis Zone graptolites is also reported, expanding the understanding of this geological time period.
ESTONIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Taniel Danelian, Claude Monnet
Summary: Based on a comprehensive dataset of middle Cambrian to Silurian radiolarian occurrences, this study investigates the diversity patterns and taxonomic evolution of radiolarian species. The research highlights significant changes in radiolarian diversity during the Darriwilian, possibly related to global changes and Earth's climate. Despite robust long-term trends in radiolarian biodiversity, the documented patterns are partly influenced by uneven sampling through space and time.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Farid Saleh, Romain Vaucher, Jonathan B. Antcliffe, Allison C. Daley, Khadija El Hariri, Khaoula Kouraiss, Bertrand Lefebvre, Emmanuel L. O. Martin, Jean-Philippe Perrillat, Pierre Sansjofre, Muriel Vidal, Bernard Pittet
Summary: The Fezouata Biota in Morocco is a unique Lower Ordovician Lagerstadtte, preserving a diverse biological assemblage with organisms typical of Cambrian Burgess Shale-type ecosystems. Most organisms were already dead and decaying on the seafloor before being buried by occasional storm-induced deposits. The non-preservation of completely cellular organisms like jellyfish in the Fezouata Shale is attributed to pre-burial decay. Despite preservation biases, the autochthonous assemblages offer a unique opportunity to understand Early Palaeozoic seas compared to other Cambrian BST biotas.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geology
Mercedes Barros, Cecilia Pavon Pivetta, Daniel A. A. Gregori, Leonardo Benedini, Leonardo Strazzere, Mauro C. C. Geraldes, Paulo Marcos
Summary: The Comallo volcanic sedimentary Complex in the western North Patagonian Region is formed by the development and collapse of Plinian-type eruptive columns of rhyolitic and dacitic composition. The synchronous deposits are found in alluvial and lagoon environments. The derived zircon grains indicate the possibility of melting Paleoproterozoic and Mesoproterozoic crust. Basaltic and andesitic lava flows and pyroclastic deposits appear in the upward sequence, which are related to sustained pyroclastic fountains with a U-Pb zircon age of 185 Ma. The volcanic rocks are possibly derived from Paleoproterozoic, Mesoproterozoic, and Neoproterozoic crust affected by juvenile magmas in volcanic-arc environments. Chemical and isotopic variations are mainly caused by changes in the local and regional tectonic conditions, the thickness of the continental crust, as well as the dip and age of the subducted oceanic crust.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geography, Physical
Thomas Servais, David A. T. Harper, Wenhui Wang
Summary: This special issue presents different perspectives on the Ordovician radiations, featuring 16 selected papers that provide insights into the various radiations that occurred during the Ordovician Period. The study suggests that the Cambrian and Ordovician radiations are actually artificially separated by the late Cambrian 'Furongian Biodiversity Gap', and a long-term early Palaeozoic radiation is becoming more visible.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Energy & Fuels
Jia-Qi Yang, Jun-Tao Zhang, Zhi-Liang He, Tao Zhang
Summary: Reconstructing paleoenvironments is crucial for understanding the development and evolution of carbonate reservoirs. The Middle Ordovician Period is significant for its greenhouse conditions and biological evolution. By analyzing the carbonate rocks in the Dingbei area of the Ordos Basin, the paleoenvironment was reconstructed, revealing high seawater paleotemperature, suboxic-anoxic paleoredox conditions, and high seawater paleosalinity. The presence of planktonic organisms led to an increase in total organic carbon, providing a supplementary source for natural gas. The dissolution of gypsum and its residual presence further contributed to the preservation of natural gas. This study provides valuable data and a theoretical basis for natural gas exploration.