Review
Paleontology
Gerd Geyer, Ed Landing, Stefan Meier, Stefan Hoehn
Summary: This article discusses the discovery of a likely graptolite fossil in the lowest Wuliuan strata of the Franconian Forest, which is believed to be the oldest graptolithoid hemichordate found in West Gondwana and possibly the oldest graptolite known to date. The fossil, belonging to the poorly known genus Ovetograptus of the Dithecodendridae family, is a delicate, erect, apparently unbranched rhabdosome with narrow thecae. The report also provides an overview of pre-Furongian graptolithoids and makes slight corrections to the stratigraphic position of previously reported species.
Article
Geography, Physical
T. Palacios, S. Jensen, J. J. Alvaro, J. F. Santos Zaldeugui, L. Eguiluz, F. Corfu, J. I. Gil Ibarguchi
Summary: The detailed record of diagnostic acritarchs from the volcanosedimentary Vallehondo and Playon formations allows the establishment of a fine acritarch-based chronostratigraphy applicable to the Acado-Baltic Province. The maximum diversification of acritarchs in the Miaolingian coincides with the onset of basaltic pillow lava flows in the Playon Formation, reflecting a major rifting episode.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Kamal Mghazli, Nezha Lazreq, Gerd Geyer, Ed Landing, Moulay Ahmed Boumehdi, Nasrrddine Youbi
Summary: Diverse helcionelloid molluscs, probable polychaetes, and sclerites of other metazoan groups have been discovered in the Lemdad syncline in southern Morocco. These findings provide valuable insights into paleogeographic connections and interregional and continental biostratigraphic correlation.
JOURNAL OF AFRICAN EARTH SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Zhiliang Zhang, Mansoureh Ghobadi Pour, Leonid E. Popov, Lars E. Holmer, Feiyang Chen, Yanlong Chen, Glenn A. Brock, Zhifei Zhang
Summary: This study in South China reveals the oldest Cambrian brachiopod-trilobite association, providing potential for stratigraphic correlation. The new species Eoobolus incipiens represents one of the earliest linguliform brachiopods.
Article
Geography, Physical
Zhiyao Zhang, Guangyou Zhu, Guanghui Wu, Tingting Li, Xueqian Feng, Yinghao Jing
Summary: The study presents carbon and oxygen isotope data of Ediacaran-Cambrian siliciclastic-carbonate from northwestern Tarim Craton, proposing correlations with other basins and suggesting the involvement of Tarim Craton in the Pan-African Orogeny during the assembly of Gondwana.
GLOBAL AND PLANETARY CHANGE
(2022)
Review
Geosciences, Multidisciplinary
Simon A. F. Darroch, Alison T. Cribb, Luis A. Buatois, Gerard J. B. Germs, Charlotte G. Kenchington, Emily F. Smith, Helke Mocke, Gretchen R. O'Neil, James D. Schiffbauer, Katie M. Maloney, Rachel A. Racicot, Katherine A. Turk, Brandt M. Gibson, John Almond, Bryce Koester, Tom H. Boag, Sarah M. Tweedt, Marc Laflamme
Summary: The Ediacaran-Cambrian transition is a significant geobiological revolution in Earth history, involving multiple waves of evolutionary radiation and apparent mass extinctions. Factors such as ecosystem engineering, trace fossils, and bioturbation may have played crucial roles during this period.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geochemistry & Geophysics
Matheus F. de Lima, Fabricio A. Caxito, Ross Large, Indrani Mukherjee, Gabriel J. Uhlein, Joao Pedro T. M. Hippertt, Pedro T. M. Hippertt, Samuel A. Moura, Juliana Okubo, Lucas Warren
Summary: Trace element analysis of syn-sedimentary pyrite is used to track the redox and nutrient variations in the Ediacaran-Cambrian Bambui Group of eastern Brazil. The results indicate the importance of oxidative continental weathering and the development of ferruginous bottom water conditions, which had a negative impact on the development of Ediacaran-Cambrian ecosystems.
Article
Evolutionary Biology
John R. Paterson, Diego C. Garcia-Bellido, Gregory D. Edgecombe
Summary: Two species of Radiodonta from the Emu Bay Shale in South Australia have been revised based on new field collections and recent advances in knowledge of radiodonts. Anomalocaris briggsi is designated as the type species of a new genus called Echidnacaris, while the less common species is named Anomalocaris daleyae. Oral cones have been assigned to both species, and the oral cone of Echidnacaris briggsi is the best preserved among all known radiodonts. Shared characters of the oral cones support the relationship between Tamisiocarididae and Anomalocarididae. Unique eye characters found in E. briggsi are tentatively regarded as diagnostic for Echidnacaris.
JOURNAL OF SYSTEMATIC PALAEONTOLOGY
(2023)
Article
Geochemistry & Geophysics
Yajun Xu, Xiao Liang, Peter A. Cawood, Jian-Wei Zi, Hangchuan Zhang, Jia Liu, Yuansheng Du
Summary: By analyzing the U-Pb ages of detrital monazite from Cambrian sedimentary rocks, we suggest that South China was located outboard of northeastern India. The detrital monazite ages indicate input from earliest Cambrian metapelites and provide tighter constraints on the paleogeography of South China compared to detrital zircon data alone.
Article
Geosciences, Multidisciplinary
Fred T. Bowyer, Andrey Yu Zhuravlev, Rachel Wood, Graham A. Shields, Ying Zhou, Andrew Curtis, Simon W. Poulton, Daniel J. Condon, Chuan Yang, Maoyan Zhu
Summary: This study presents a new delta C-13(carb) composite reference curve for the Ediacaran Nama Group and proposes four possible global age models for the Ediacaran-Cambrian transition. These models reveal the variability in the terminal Ediacaran and support the pre-BACE first appearance of Cambrian-type shelly fossils in Siberia and possibly South China.
EARTH-SCIENCE REVIEWS
(2022)
Article
Paleontology
Matilde Sylvia Beresi, Osvaldo Luis Bordonaro
Summary: This study reports and describes a chancelloriid fauna for the first time, which exhibits taxonomic composition similar to other Cambrian species in different regions. Based on the construction of sclerites, different articulatory facet types can be used to distinguish between chancelloriid species, and the number of rays is closely related to the arrangement of sclerite rays. This study is significant for understanding the diversity of chancelloriid fauna in the middle Cambrian platform of the Precordillera.
Article
Paleontology
Yeongju Oh, Dong-Chan Lee, Dong-Jin Lee, Jeong-Gu Lee
Summary: Helcionelloids from the Korean Peninsula have been revised based on a re-examination of type specimens and new material. The fauna consists of various species with unique features, ranging stratigraphically from the Maochuangian to the lower Hsuchuangian stages. Unusual septal features in the apical region of the Korean helcionelloids could have implications for molluscan evolution.
Review
Geosciences, Multidisciplinary
Yousef Zoleikhaei, Jacob A. Mulder, Peter A. Cawood
Summary: By analyzing the detrital zircon and rutile from the early Paleozoic Lalun Formation in Iran, it was found that most of the detrital sediments originated from the Neoproterozoic age, and the Arabian-Nubian Shield may be a more suitable source for the formation. This study reveals a complex pattern of sediment dispersal along the northern margin of Gondwana and challenges the idea of a well-mixed, far-travelled sand sheet.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geology
Rafael Oliveira Silva, Mariangela Garcia Praca Leite, Isaac Rudnitzki, Wagner Souza-Lima
Summary: This study focuses on the Permian sedimentology of the Sergipe-Alagoas Basin in northeastern Brazil, identifying six facies associations that reflect the paleoenvironmental conditions of a coastal environment that was part of a shallow epicontinental sea in West-Central Gondwana. The deposits show characteristics of eolian, desiccation structures, and mixed carbonate-siliciclastic facies, with an early diagenetic silicification being the main diagenetic feature. Similarities were observed with Eocene glass ramps of Australia, and a relationship with the Permian Chert Event is suggested.
SEDIMENTARY GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Eben Blake Hodgin, Juan Carlos Gutierrez-Marco, Jorge Colmenar, Francis A. Macdonald, Victor Carlotto, James L. Crowley, Justin R. Newmann
Summary: This study provides detailed insights into the tectonic and evolutionary history of the Eastern Cordillera in Peru, with important evidence related to the accretion of the Arequipa Terrane. It sheds light on the early Paleozoic tectonic history of the region and presents a new tectonic model explaining the late Neoproterozoic to early Cambrian collision events.
Article
Geosciences, Multidisciplinary
Gerd Geyer, Ed Landing
JOURNAL OF AFRICAN EARTH SCIENCES
(2020)
Article
Paleontology
Gerd Geyer, Miguel Caldeira Pais, Thomas Wotte
Article
Paleontology
Gerd Geyer, John S. Peel
JOURNAL OF PALEONTOLOGY
(2020)
Article
Geosciences, Multidisciplinary
Ed Landing, Mark D. Schmitz, Gerd Geyer, Robin B. Trayler, Samuel A. Bowring
Summary: New U-Pb radioisotopic ages on early Cambrian volcanic zircons have led to the development of a high-resolution Bayesian age model, which has constrained the first occurrences and zonations of West Gondwanan archaeocyaths and trilobites in southern Morocco. The results show that the oldest Moroccan trilobite fragments are approximately 1 million years younger than those in Siberia, and around 0.5 million years older than the oldest Avalonian trilobites. The study also highlights taxonomic differences in the oldest trilobites between Cambrian paleocontinents, suggesting a possible appearance of the group as late as around 530 million years ago.
GEOLOGICAL MAGAZINE
(2021)
Article
Geosciences, Multidisciplinary
Ed Landing, Robert L. Ripperdan, Gerd Geyer
GEOLOGICAL MAGAZINE
(2020)
Article
Paleontology
Ed Landing, Gerd Geyer
Summary: The Nigali Dhar syncline succession in the north Indian margin reveals the deposition, fauna, and passive margin evolution from the Terminal Ediacaran to late early Cambrian. The study of ichnofauna in the Upper Tal Group provides insight into paleoenvironmental changes and biological evolution, contributing to the understanding of Lesser Himalaya geologic evolution. The KDF-type ichnofaunas do not support a tropical location of Avalonia, highlighting its unique lithofacies and biotas as a high-latitude continent unrelated to Gondwana.
ICHNOS-AN INTERNATIONAL JOURNAL FOR PLANT AND ANIMAL TRACES
(2021)
Article
Paleontology
Ed Landing, Gerd Geyer, Igor A. Jirkov, Stefano Schiaparelli
Summary: The tiny snail-like conchs of Pelagiella Matthew play a key role in discussions of lophotrochozoan and mollusc evolution during the Cambrian period. However, difficulties in distinguishing between Pelagiella species, their widespread distribution, long lifespan, and the assumption that all Pelagiella spp. are gastropods have led to controversy surrounding the genus. Reevaluation of Pelagiella exigua reveals it to be a polychaete, likely belonging to the newly proposed genus Pseudopelagiella.
PAPERS IN PALAEONTOLOGY
(2021)
Editorial Material
Geosciences, Multidisciplinary
E. D. Landing, Robert L. Ripperdan, Gerd Geyer
Summary: There is controversy regarding the naming of a global negative carbon isotope excursion in the uppermost Cambrian. The HERB Event has met the standards for chemostratigraphic units since 1992, while the TOCE excursion has gone through four temporally distinct events before being synonymized with HERB. However, TOCE fails to meet the recommendations for a formal chemostratigraphic unit. One TOCE homonym is a synonym of HERB.
GEOLOGICAL MAGAZINE
(2022)
Article
Paleontology
Gerd Geyer, Ed Landing, Anna Zylinska
Summary: Eccaparadoxides is a geographically widely distributed trilobite genus with problematic morphologic characteristics for differentiation. Tail parts offer reliable criteria while species known only from cranidia cannot be assigned with certainty. The study refines biostratigraphy and proposes new species within the genus.
Review
Paleontology
Gerd Geyer, Ed Landing, Stefan Meier, Stefan Hoehn
Summary: This article discusses the discovery of a likely graptolite fossil in the lowest Wuliuan strata of the Franconian Forest, which is believed to be the oldest graptolithoid hemichordate found in West Gondwana and possibly the oldest graptolite known to date. The fossil, belonging to the poorly known genus Ovetograptus of the Dithecodendridae family, is a delicate, erect, apparently unbranched rhabdosome with narrow thecae. The report also provides an overview of pre-Furongian graptolithoids and makes slight corrections to the stratigraphic position of previously reported species.
Article
Geosciences, Multidisciplinary
Mehdi Daraei, Aram Bayet-Goll, Gerd Geyer, Nasrin Bahrami
Summary: The Deh-Molla Formation in northern Iran provides valuable insights into global sea-level fluctuations and climate changes during the Furongian Epoch. Its sedimentological characteristics indicate deposition on a sloping platform with fluctuating environmental conditions. The formation's ribbon rocks suggest a temperate latitude zone with seasonal influence from tropical monsoons.
GEOLOGICAL JOURNAL
(2023)
Article
Geosciences, Multidisciplinary
Kamal Mghazli, Nezha Lazreq, Gerd Geyer, Ed Landing, Moulay Ahmed Boumehdi, Nasrrddine Youbi
Summary: Diverse helcionelloid molluscs, probable polychaetes, and sclerites of other metazoan groups have been discovered in the Lemdad syncline in southern Morocco. These findings provide valuable insights into paleogeographic connections and interregional and continental biostratigraphic correlation.
JOURNAL OF AFRICAN EARTH SCIENCES
(2023)
Letter
Biology
Ed Landing, Bjoern Kroeger, Stephen R. Westrop, Gerd Geyer
COMMUNICATIONS BIOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Ed Landing, Mark D. Schmitz, Stephen R. Westrop, Gerd Geyer
Summary: High-precision U-Pb zircon dating of SE Newfoundland tuffs has provided new insights into the Avalonian Lower-Middle Cambrian boundary. The study also reveals the presence of an unconformity between the Brigus and Chamberlain's Brook formations. These findings contribute to our understanding of the geological evolution of Avalonia.
GEOLOGICAL MAGAZINE
(2023)
Article
Paleontology
Alfred Uchman, Gerd Geyer
ICHNOS-AN INTERNATIONAL JOURNAL FOR PLANT AND ANIMAL TRACES
(2020)