Article
Biology
Longlong Shan, Kui Yan, Yuandong Zhang, Jun Li, Thomas Servais
Summary: This study used a selection of the most abundant acritarch taxa from the Cambrian and Ordovician of China to understand the evolution of phytoplankton palaeoecological patterns over time. The research found that acritarch microfloras were limited to inshore environments during the early Cambrian and gradually extended to offshore marine habitats, with a prominent shift near the Cambrian-Ordovician boundary, confirming the onset of the 'Ordovician plankton revolution'. The acritarch morphotypes evolved from low-diversity assemblages in the early Cambrian to highly diverse assemblages with complex morphologies in the Early and Middle Ordovician.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Wei Dan, J. Brendan Murphy, Gong-Jian Tang, Xiu-Zheng Zhang, William M. White, Qiang Wang
Summary: The origin of the controversial Cambrian-Ordovician tectono-magmatic events in NE Gond-wana and adjacent peri-Gondwanan terranes is discussed. A potential silicic large igneous province (LIP) called the Pinghe silicic LIP is proposed, consisting of granitic rocks formed between ca. 510 Ma and 460 Ma. The recognition of this belt of granitic rocks helps refine tectonic reconstructions of Gondwana and models for the rifting of terranes from its northern margin.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2023)
Article
Geochemistry & Geophysics
Leibo Bian, Anthony Chappaz, Niels H. Schovsbo, Xiaomei Wang, Wenzhi Zhao, Hamed Sanei
Summary: The late Cambrian extinction - Early Ordovician biodiversification is a crucial lower Paleozoic biological change, but the mechanisms behind this transition are not well understood. This study reconstructed the paleoenvironmental changes and assessed the Cambro-Ordovician biological turnover. The results showed that depositional environments became extremely sulfidic with lower nutrient inputs, leading to the Steptoean Positive Carbon Isotope Excursion event. Intense volcanic activity in the early Jiangshanian contributed to recurrent bio-calamities. Later, enhanced terrestrial weathering and oceanic water upwelling facilitated biological recovery and laid the foundation for the Great Ordovician Biodiversification Event.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geography, Physical
Chenlin Hu, Changcheng Han, Jinghui Ma, Wenfeng Wang, Fangyu Zhao, Wenxuan Sun
Summary: This study investigated the sedimentary differentiation and anisotropy of magnetic susceptibility (AMS) of the Tarim Carbonate Platform (TCP) in order to infer the paleowind directions during each epoch of the Cambrian-Ordovician and constrain its paleogeographic location. The results showed that the prevailing wind directions of the Early, Middle, and Late Cambrian were 226 degrees +/- 42 degrees, 207 degrees +/- 43 degrees, and 193 degrees +/- 36 degrees from present north, respectively, while those of the Early, Middle, and Late Ordovician were 178 degrees +/- 39 degrees, 165 degrees +/- 43 degrees, and 155 degrees +/- 52 degrees from present north, respectively.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Multidisciplinary Sciences
Xi-ping Dong, Baichuan Duan, Jianbo Liu, Philip C. J. Donoghue
Summary: In this study, researchers used synchrotron radiation X-ray tomographic microscopy to study a new collection of fossilized embryos from the Wangcun fossil Lagerstatte in Hunan, South China. The study revealed new insights into the soft tissue anatomy, phylogenetic affinity, and evolutionary significance of Markuelia hunanensis.
ROYAL SOCIETY OPEN SCIENCE
(2022)
Article
Biology
Nevin P. Kozik, Seth A. Young, Anders Lindskog, Per Ahlberg, Jeremy D. Owens
Summary: Using multiple proxies, we studied two drill core successions in the Baltic and Scandinavian regions, revealing persistently anoxic and sulfidic bottom water conditions. Trace metal datasets suggest nuanced changes in global anoxic and sulfidic conditions along continental margins. Thallium isotope data indicate a global expansion of oxygenated shelf and deeper marine environments from the late Cambrian into the Early Ordovician. These findings provide evidence for increased marine oxygen concentrations as a key mechanism for the Ordovician radiation of marine life.
Article
Multidisciplinary Sciences
Xi-ping Dong, Baichuan Duan, Jianbo Liu, Philip C. J. Donoghue
Summary: In this study, synchrotron radiation X-ray tomographic microscopy (SRXTM) was used to study a new collection of fossil embryos from the Wangcun fossil Lagerstatte in Hunan, South China. The findings reveal the first record of fossilized nervous system in a scalidophoran, with detailed descriptions of mineralization phases and interpretation of associated structures, providing insights into the soft tissue anatomy and evolutionary significance of Markuelia.
ROYAL SOCIETY OPEN SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Jin-bo Hou, Nigel C. Hughes, Melanie J. Hopkins
Summary: Efficient extraction of oxygen from ambient waters was crucial for the early arthropods. They maximized gill surface area to enhance oxygen uptake, but this also led to gill contamination due to exposure to the external environment. The presence of setae on the walking legs of Olenoides serratus and on the gill shaft of Triarthrus eatoni suggests that grooming was used to remove particles trapped among the gill filaments, similar to modern crustaceans.
GEOLOGICAL MAGAZINE
(2023)
Article
Multidisciplinary Sciences
Russell D. C. Bicknell, Patrick M. Smith
Summary: Injured trilobite specimens provide insights into the predator-prey systems of Paleozoic era, specifically how an extinct group of arthropods responded to traumatic experiences such as failed predation. The study presents new examples of injured trilobites and discusses their possible origins and predators.
Article
Fisheries
Pierre Bourdaud, Frida Ben Rais Lasram, Emma Araignous, Juliette Champagnat, Samantha Grusd, Ghassen Halouani, Tarek Hattab, Boris Leroy, Quentin Nogues, Aurore Raoux, Georges Safi, Nathalie Niquil
Summary: Climate change has irreversible impacts on ecosystems, with a focus on predicting future distribution of marine species biomass at the community level. The study in the Bay of Seine demonstrates that climate change scenarios can influence species dynamics and ecosystem stability, emphasizing the importance of considering trophic interactions in simulations to efficiently forecast potential impacts.
FISHERIES OCEANOGRAPHY
(2021)
Article
Energy & Fuels
Xiao-Wei Zheng, Niels-H. Schovsbo, Lei-Bo Bian, Arka Rudra, Hamed Sanei
Summary: This study used organic geochemistry and organic petrology to investigate the depositional environment, organic matter characteristics, and thermal maturity of the Cambrian-Ordovician organic-rich marine shales in the Baltic Basin. The results showed that as the maturity increased, solid bitumen became more abundant and dispersed. Additionally, a Semifusinite-like maceral was observed in one of the studied samples, indicating a possible intrusion of Permo-Carboniferous dolerite dikes. The pyrolysis data also supported the presence of immature, early mature, and over-mature samples.
Article
Environmental Sciences
Daniel R. Hadley, Daniel B. Abrams, Devin H. Mannix, Cecilia E. Cullen
Summary: This study discusses the depletion of the Cambrian-Ordovician sandstone aquifer and develops a conceptual framework using a participatory groundwater modeling approach. Results show that even with a 35% reduction in water use, many areas remain at high or severe risk. The participatory modeling process highlights the importance of considering pumping levels at production wells for assessing aquifer sustainability and risk.
WATER RESOURCES RESEARCH
(2021)
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
Evolutionary Biology
B. Gudveig Baarli, Bing Huang, Luana S. Maroja
Summary: This study investigates the early evolution of the Atrypida order through Silurian time. It presents a phylogenetic analysis of 70 genera and 41 characters, revealing the relationships and evolutionary patterns within the group. The study also suggests the need for subdivision and redefinition of certain subfamilies and families within the order. The findings shed light on the importance of the Great Ordovician Biodiversification Event and Late Ordovician Mass Extinction.
JOURNAL OF SYSTEMATIC PALAEONTOLOGY
(2022)
Article
Paleontology
Paul Johnston, Michael Streng
Summary: The bulk sampling of carbonate units in the middle Cambrian in Utah has yielded abundant silicified stenothecoids, including previously unreported species. These fossils suggest a phylogenetic relationship between Stenothecoida and Brachiopoda, indicating a pan-brachiopod stem group that may have evolved from eccentrothecimorph tommotiids.
ACTA PALAEONTOLOGICA POLONICA
(2021)
Article
Paleontology
Jisuo Jin, Robert B. Blodgett, David A. T. Harper, Christian M. O. Rasmussen
Summary: The Late Ordovician Tcherskidium fauna, characterized by large and ribbed shells, was mainly distributed in the paleoequatorial and northern paleotropical zones, while the Southern Hemisphere was influenced by cold-water invasions.
JOURNAL OF PALEONTOLOGY
(2022)
Article
Biology
Fan Liu, Christian B. Skovsted, Timothy P. Topper, Zhifei Zhang
Summary: Doliutheca orientalis is a fossil species from the early Cambrian of the Three Gorges area in southern China. It possesses unique shell structures and belongs to the group of hyoliths, showing variations in both internal and external morphology.
Article
Biology
ZhiFei Zhang, Martin R. Smith, XinYi Ren
Summary: The main animal lineages diversified in the Cambrian period, while the diversity at lower taxonomic ranks emerged gradually over the next 500 million years. Annelid worms appear to follow this pattern, with early-diverging crown-group annelids found in Cambrian Burgess Shale deposits and more derived polychaete families appearing in later periods. However, the discovery of 15 new fossils of the 'phoronid' Iotuba chengjiangensis challenges this view, as they exhibit similarities to derived polychaete families, indicating an earlier origin of modern annelid diversity.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Biology
Luoyang Li, Marissa J. Betts, Hao Yun, Bing Pan, Timothy P. Topper, Guoxiang Li, Xingliang Zhang, Christian B. Skovsted
Summary: This study reveals that the skeletons of early Cambrian mollusks and hyoliths are composed of fibrous microstructures made of calcite, which had not been discovered before. Additionally, it shows that the shells of these early animals were mainly composed of aragonite. This has important implications for understanding the significance of early biomineralization and its relationship with seawater chemistry.
Article
Biochemistry & Molecular Biology
Yue Liang, Luke C. Strotz, Timothy P. Topper, Lars E. Holmer, Graham E. Budd, Yanlong Chen, Ruisen Fang, Yazhou Hu, Zhifei Zhang
Summary: Morphology is important to understand diversification and macroevolution. Lingulid brachiopods were diverse during the early Palaeozoic but decreased over time. Geometric morphometrics analysis shows that maximum morphospace occupation was reached in the Early Ordovician. The decline in diversity was associated with the end Ordovician mass extinction and evolutionary contingency.
Article
Paleontology
Bing Huang, Di Chen, David A. T. Harper, Jiayu Rong
Summary: 'Strophodontoid' brachiopods were the dominant group of strophomenide brachiopods during the Silurian and Devonian periods. Their evolution, characterized by the development of denticles along the hinge line, was linked to the disappearance of dental plates and teeth. The discovery of three phenotypes of E. parvicostellata in a single fossil bed suggests a speciation process, and the population differentiation between two phases of the Late Ordovician mass extinction event indicates a Hirnantian origination of the 'strophodontoid' morphology.
Article
Biology
Yaqin Qiang, Junfeng Guo, Guoxiang Li, Zuchen Song, Jiaxin Peng, Jie Sun, Jian Han, Zhifei Zhang
Summary: Aldanella attleborensis, commonly known as a mollusk fossil, has been suggested as a potential marker for defining the base of Cambrian Stage 2. This study re-evaluated the taxonomy of Aldanella yanjiaheensis based on specimens collected from the Yanjiahe Formation. The results suggest that A. yanjiaheensis is a junior synonym of A. attleborensis, indicating its strong potential for global correlation. The wide distribution and distinct morphology of A. attleborensis make it significant for the subdivision and correlation of Cambrian Stage 2.
Editorial Material
Multidisciplinary Sciences
Kaiyue He, Jianni Liu, Jian Han, Qiang Ou, Ailin Chen, Zhifei Zhang, Dongjing Fu, Hong Hua, Xingliang Zhang, Degan Shu
Summary: In this study, the researchers examined over 8000 specimens of yunnanozoans and found no evidence of cellular cartilage or fibrillin. They also reject the idea that yunnanozoans are stem-group vertebrates based on their ultrastructure and morphology.
Article
Biology
Mei Luo, Fan Liu, Yue Liang, Luke C. Strotz, Jiayue Wang, Yazhou Hu, Baopeng Song, Lars E. Holmer, Zhifei Zhang
Summary: Small skeletal fossils from the early Cambrian Guojiaba Formation in southern Shaanxi, China were reported for the first time. The fossils include a wide variety of skeletal clades, such as brachiopods, sphenothallids, archaeocyaths, bradoriids, sponge spicules, echinoderm plates, and trilobite spines. The archaeocyaths found in the Guojiaba Formation are older than those previously described from the Xiannvdong Formation. The fossil assemblages from the Guojiaba Formation resemble those from the upper Yu'anshan Formation (Chengjiang Fauna) in eastern Yunnan Province, supporting the correlation of the Guojiaba Formation with the Chiungchussuan Stage (Stage 3 of Cambrian Series 2).
Article
Geology
David A. T. Harper
Summary: Despite its small size, Ireland features eight Caledonian tectonic terranes, six of which contain Ordovician brachiopod assemblages. These terranes provide evidence of the early and late stages of the Iapetus Ocean's formation and destruction, with latitude-sensitive brachiopod faunas in the Middle and early Late Ordovician and more cosmopolitan faunas in the later Ordovician.
ESTONIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Geology
David A. T. Harper, Tonu Meidla, Thomas Servais
Summary: The Ordovician System was hidden for nearly a century as Murchison and Sedgwick argued over their Silurian and Cambrian systems. It is a long geological period characterized by major magmatic and plate tectonic activity, with significant fluctuations in climate and sea levels and the first mass extinction of marine invertebrates. The period is unique with thalassocratic features and isolated land areas. The introduction of the Ordovician System by Charles Lapworth and subsequent research led to the recognition and understanding of biological and geological events during the period.
ESTONIAN JOURNAL OF EARTH SCIENCES
(2023)
Article
Paleontology
Rao Fu, Yazhou Hu, Timothy P. Topper, Fan Liu, Yue Liang, Zhifei Zhang
Summary: Sphenothallus is a tubular organism that has been discovered for the first time in North China in Jiangsu Province. The specimens show typical characteristics of the genus, but with higher rates of apertural expansion and tube curvature in early growth stages. As the aperture diameter increases, the transverse cross-section and wall thickness of the tube change. This discovery extends the palaeogeographic range of Sphenothallus during the Cambrian.
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
Ecology
Fan Liu, Christian B. Skovsted, Timothy P. Topper, Zhifei Zhang
Summary: The study revises a small hyolith originally documented as Ambrolinevitus ventricosus based on new material, and reassigns it as Paramicrocornus. The classification analysis of Cambrian and Ordovician hyoliths reveals the evolution model of hyolith skeleton and soft-part anatomy, with Paramicrocornidae as the closest relative of hyolithids.
BMC ECOLOGY AND EVOLUTION
(2022)
Article
Multidisciplinary Sciences
Qiang Ou, Degan Shu, Zhifei Zhang, Jian Han, Heyo Van Iten, Meirong Cheng, Jie Sun, Xiaoyong Yao, Rong Wang, Georg Mayer
Summary: This research reports a new polypoid cnidarian, named "Nailiana elegans". The specimen was found in the early Cambrian Chengjiang biota and shows a level of organization similar to extant cnidarians. Phylogenetic analyses suggest it belongs to the stem lineage of Anthozoa, and one specimen provides evidence of predation on an epifaunal lingulid brachiopod.