Article
Geosciences, Multidisciplinary
Valentin Bault, Diego Balseiro, Claude Monnet, Catherine Cronier
Summary: Trilobites were the most successful clade of marine invertebrates during the Cambrian, but their diversity declined after the end-Ordovician extinction event. This study investigates the evolutionary history and diversity dynamics of trilobites after the crisis, revealing different faunas and environmental influences.
EARTH-SCIENCE REVIEWS
(2022)
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
Geography, Physical
Daniela S. Monti, Viviana A. Confalonieri, M. Franco Tortello
Summary: This study investigates the biogeographic histories of two cosmopolitan groups of Olenida, Hypermecaspididae and Parabolinella (Olenidae). Different biogeographical models were compared, and the results suggest that jump dispersal was an important speciation strategy for both groups. Vicariance was found to be unimportant. The dispersal patterns of Parabolinella were influenced by ocean currents, while those of Hypermecaspididae were not. Island hopping and creeping were the main dispersal mechanisms for both groups. The western margin of Gondwana played a significant role as a dispersal center during the Furongian and Early Ordovician.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Yiying Deng, Junxuan Fan, Shuhan Zhang, Xiang Fang, Zhongyang Chen, Yukun Shi, Haiwen Wang, Xinbing Wang, Jiao Yang, Xudong Hou, Yue Wang, Yuandong Zhang, Qing Chen, Aihua Yang, Ru Fan, Shaochun Dong, Huiqing Xu, Shuzhong Shen
Summary: The study utilized high-resolution chronostratigraphy to reveal two major biological events in the early Paleozoic era: GOBE and LOME. GOBE started in the early Ordovician and ended at the Darriwilian boundary, consisting of two major radiation phases; while the Late Ordovician witnessed two extinction events resulting in a regional species loss of approximately 67%.
EARTH-SCIENCE REVIEWS
(2021)
Article
Zoology
Jonathan M. Adrain, Francesc Perez-Peris
Summary: A diverse mid-Darriwilian trilobite fauna from the Table Cove Formation in western Newfoundland has been found, with additional morphological information revealed by silicified faunas on the east coast, including new genera and species. Many of these species are early Laurentian members of the diversifying Whiterock Fauna, with some potentially near the base of their respective clades. The concept of Sphaerexochinae is now restricted to the genus Sphaerexochus, with new classifications for other taxa based on multiple putative synapomorphies.
Article
Geography, Physical
Fernanda Serra, Diego Balseiro, Beatriz G. Waisfeld
Summary: Through the study of important trilobite assemblages from the late Cambrian to Early Ordovician in northeastern Argentina, we have discovered changes in the structure of assemblage disparity during extinction events, which are related to the regulation of local coexistence. Additionally, the temporal separation of diversity and disparity trends may be related to ecological hierarchy. These findings suggest a higher ecological complexity than previously expected during the early stages of the Ordovician Radiation.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Paleontology
Russell D. C. Bicknell, Julien Kimmig
Summary: By examining malformed trilobite specimens, we can gain insight into how extinct animals responded to injuries, developmental malfunctions, and pathologies. A slab containing eight individuals of the asaphid trilobite Pseudogygites latimarginatus from Canada is examined, and two individuals with malformations are documented. These malformations are considered injuries that demonstrate how P. latimarginatus recovered from failed predation attacks, providing possible evidence of predator groups. The cluster is interpreted as an aggregation that was preserved prior to a molting event. The study of this gregarious behavior has implications for understanding the paleoecology of Ordovician asaphid trilobites.
NEUES JAHRBUCH FUR GEOLOGIE UND PALAONTOLOGIE-ABHANDLUNGEN
(2023)
Article
Geography, Physical
Xin Wei, Jianbo Liu, Renbin Zhan, Zhiqiang Zhou, Guanzhou Yan
Summary: This study reviewed the available data on the distribution of Middle-early Late Ordovician trilobites in South China and analyzed their diversity dynamics. The results revealed three macroevolutionary phases and three faunal turnovers. Changes in sea level and substrate conditions played a significant role in the faunal replacements. The radiation of trilobites was primarily influenced by the development and expansion of the Whiterock Fauna, with a shift towards outer platform environments over time. Climate cooling, substrate conditions, and increased oxygen levels and nutrients likely provided favorable conditions for trilobite radiation during the Middle Ordovician.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2024)
Review
Ecology
Christian M. O. Rasmussen, Thijs R. A. Vandenbroucke, David Nogues-Bravo, Seth Finnegan
Summary: The Late Ordovician mass extinction event, although initially regarded as an outlier, is now recognized as a prolonged and punctuated decline in biodiversity, affected by changes in atmospheric composition, ocean chemistry, and viable habitat area. This evolving view suggests similarities in extinction drivers to other major extinctions and offers important lessons about the current human-induced biodiversity crisis. Even this very ancient and exceptional event provides insights into the intensifying 'sixth mass extinction'.
TRENDS IN ECOLOGY & EVOLUTION
(2023)
Article
Geology
Bryce B. Barney, Ethan L. Grossman
Summary: The study indicates that the Late Ordovician climate in the Cincinnati Arch was warmer than modern subtropical seas, likely influenced by the upwelling of cool water. Though previous studies have reported higher temperatures, correcting for reordering effects did not significantly change the overall findings.
Article
Geochemistry & Geophysics
P. Kosakowski, A. Zakrzewski, M. Waliczek
Summary: The Baltic Syneclise is a Paleozoic basin along the western margin of the East European Craton, where commercial amounts of hydrocarbons have been found. Good quality source rocks in the Middle-Upper Cambrian and Tremadocian bituminous shales have contributed to conventional and unconventional hydrocarbon explorations in the region. Geochemical analyses indicate overall good to very good source rock quality in the Middle-Late Ordovician and Early Silurian horizons.
Article
Geography, Physical
Yangbo Lu, Fang Hao, Detian Yan, Yongchao Lu
Summary: The study conducted on bentonite beds-bearing intervals from the Upper Ordovician Wufeng Formation in South China reveals the short-term and long-term impacts of volcanic activity on the paleoenvironment. Short-term effects include environmental disruptions such as ocean fertilization and warmer climate, while the long-term effects show a correlation between distribution of bentonite beds and global sea-level fluctuations, suggesting a cumulative heating effect from intense volcanic activities in South China.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Multidisciplinary Sciences
Nevin P. Kozik, Seth A. Young, Sean M. Newby, Mu Liu, Daizhao Chen, Emma U. Hammarlund, David P. G. Bond, Theodore R. Them II, Jeremy D. Owens
Summary: This study explores previously unexplored thallium isotope records from two paleobasins, revealing two distinct and rapid excursions in global marine redox conditions during the Late Ordovician. The strong temporal link between these perturbations and extinctions suggests that dynamic marine oxygen fluctuations played a major role in the mass extinction, which has important implications for modern deoxygenation and biodiversity declines.
Article
Geography, Physical
Peep Mannik, Oliver Lehnert, Jaak Nolvak, Michael M. Joachimski
Summary: Conodont-based delta O-18(phos) studies from two core sections in Estonia indicate a general cooling trend in the pre-Hirnantian Late Ordovician, with variable temperature changes and multiple cooling events. Results do not show a straightforward correlation between temperature trends inferred from delta O-18(phos) measurements and changes in the delta C-13 record.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Biology
Xin Wei, Zhiqiang Zhou, Renbin Zhan, Guanzhou Yan, Jianbo Liu
Summary: Seventeen trilobite species from 16 genera and 13 families have been systematically documented in the Middle Ordovician Houping Formation in Chengkou, northern Chongqing. A new species, Mioptychopyge chengkouensis sp. nov., has been described, and new morphological information has been provided for previously known species based on new specimens. The formation is home to two distinct trilobite associations, the Agerina Association and the Nileus-Illaenus Association, indicating different environmental conditions and a rise in sea level during the early Darriwilian transgression. The trilobite fauna in the formation shows strong endemicity to South China and a close biogeographic connection with east Peri-Gondwana.
HISTORICAL BIOLOGY
(2022)
