Article
Geosciences, Multidisciplinary
Stephen R. Westrop, Jennifer D. Eoff
Summary: This study presents the first record of an Upper Cambrian shelf-margin trilobite fauna from the Elvinia Zone (Steptoean; Jiangshanian) in eastern North America, based on the analysis of debris flow conglomerates in the Downes Point Member of the Shallow Bay Formation of western Newfoundland. The dominant species in this fauna is Buttsia, which shares similarities with trilobite biofacies from microbial buildups in the Gatesburg Formation of Pennsylvania.
CANADIAN JOURNAL OF EARTH SCIENCES
(2023)
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)
Review
Geosciences, Multidisciplinary
John J. Nguyen, Stephen R. Westrop, Ed Landing
Summary: The Cambrian olenid trilobite Peltura Milne-Edwards, 1840 is found in the Furongian strata of Baltica and Avalonia, playing an important role in biostratigraphic zonations in both regions. However, there is limited knowledge about this genus in Avalonian Canada. New collections from Nova Scotia revealed numerous sclerites of a new species, Peltura hutchinsoni sp. nov., which may also occur in the Parabolina lobata Zone of Baltica. Archives specimens from Sweden and Norway allowed the revision of Peltura scarabaeoides (Wahlenberg, 1821) and Peltura acutidens Brogger, 1882.
CANADIAN JOURNAL OF EARTH SCIENCES
(2022)
Article
Geography, Physical
Amelia E. Olsen, David S. Jones, David A. Fike, Sara B. Pruss
Summary: The Steptoean Positive Isotopic Carbon Excursion (SPICE) is a global disturbance of the carbon cycle that occurred in the Cambrian Period. It was first reported in western Utah and is characterized by the disappearance of trilobites and a spike in δ13C values. This study examines two sections in Utah to understand the impact of the SPICE event and its correlation with fossil abundance and facies change.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Geography, Physical
Benjamin C. Gill, Tais W. Dahl, Emma U. Hammarlund, Matthew A. LeRoy, Gwyneth W. Gordon, Donald E. Canfield, Ariel D. Anbar, Timothy W. Lyons
Summary: The study revealed widespread oxygen deficiency in the early Paleozoic deep oceans. It also identified significant changes in marine redox conditions in certain regions during the late Cambrian, linked to the SPICE event.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geology
Yazhou Hu, Luke C. Strotz, Dirk Knaust, Jiayue Wang, Yue Liang, Zhifei Zhang
Summary: Hardgrounds are stratigraphic beds that cement at or near the seafloor, and borings are important indicators for studying hardground development and the evolution of bio-erosion. The identification of borings relies on the crosscutting relationship with a hard substrate and morphological criteria. In flat-pebble conglomerates (FPC), distinguishing borings from burrows with a halo can be challenging. This study establishes criteria based on trace fossils to differentiate borings from burrows with a halo in FPC.
SEDIMENTARY GEOLOGY
(2023)
Article
Geography, Physical
Ewa Olempska, Blazej Blazejowski, Dieter Waloszek, Andreas Maas
Summary: The Furongian Slowi ' nska Formation in Poland has yielded well-preserved phosphatic fossils consisting of two distinct types - sinuously folded, coiled or spiral string-shaped coprolites and collapsed and deformed eggs or embryos. The coprolites are exceptionally complex, with multiple loops, suggesting a continuous production of faecal material. The high phosphate content indicates an organic-rich muddy bottom, and the producers of these coprolites may have been benthic worms. The second type of fossils are smooth-surfaced ellipsoidal to spherical forms, interpreted as eggs of phosphatocopid crustaceans, which are the most abundant fossils in the area.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Multidisciplinary Sciences
Ruiwen Zong
Summary: An injured specimen of Shergoldia laevigata was collected from the Furongian of Guangxi, South China, showing substantial transverse shortening of the left pleural segments and barely perceptible traces of healing. The injuries are interpreted as a sub-lethal attack from an unknown predator, potentially affecting the trilobite's molting process.
Article
Multidisciplinary Sciences
Yifan Wang, Jin Peng, Dezhi Wang, Hui Zhang, Xiuchun Luo, Yunbin Shao, Quanyi Sun, Chenchen Ling, Qiujun Wang
Summary: Moulting behaviors in trilobites are a crucial strategy during development, with studies showing variability within and between species. This study focused on the ontogenetic moulting behavior of Arthricocephalites xinzhaiheensis, revealing a gradual transition from Somersault configuration to Henningsmoen's configuration.
Article
Paleontology
James D. Holmes, John R. Paterson, Diego C. Garcia-Bellido
Summary: Trilobites, particularly the ellipsocephaloid Estaingia bilobata, play an important role in studying early animal evolution and developmental processes. This study provides insights into the post-embryonic ontogenetic series of E. bilobata, with new information on growth patterns and morphological features. The findings further support the phylogenetic relationships between the Estaingiidae, Ellipsocephalidae, and Xystriduridae.
PAPERS IN PALAEONTOLOGY
(2021)
Article
Paleontology
Joerg Maletz, Xue-Jian Zhu, Yuan-Dong Zhang
Summary: The description of benthic Graptolithina of the Guole Biota provides the first insight into the diversification of late Cambrian graptolites. The recognized species indicate a wider biogeographic distribution and a higher species level diversity for the Guole Biota.
Article
Paleontology
Stephen R. Westrop, Alyce A. Dengler
Summary: A new fossil species of Catillicephala, C. cifellii, is discovered from the mid-Cambrian margin of Laurentian North America. It is among the oldest representatives of the genus, dating back to the early Guzhangian period.
ACTA PALAEONTOLOGICA POLONICA
(2022)
Article
Paleontology
Luis Collantes, Eduardo Mayoral, Eladio Linan, Rodolfo Gozalo
Summary: New atopid trilobites from the early Cambrian Cumbres beds and Herrerias shale in northern Huelva Province, Andalusia, Spain are described and dated as middle-late Marianian (Cambrian Series 2, Stage 4). The study also recognizes the Laurentian species Pseudatops reticulatus for the first time in the Mediterranean subprovince. The associated trilobite assemblage in this study suggests an age close to the base of Cambrian Stage 4.
JOURNAL OF PALEONTOLOGY
(2021)
Article
Multidisciplinary Sciences
Yong-Xiang Li, John A. Tarduno, Wenjun Jiao, Xinyu Liu, Shanchi Peng, Shihua Xu, Aihua Yang, Zhenyu Yang
Summary: The transition of the geodynamic field during the Ediacaran Period remains unknown. However, a high-resolution magnetostratigraphic analysis of a 494.5 million-year-old section in South China reveals that the geomagnetic field was unstable during most of the Cambrian, with frequent reversals and a lack of a geocentric axial dipole field. This unusual field behavior supports the rotational stability of the solid Earth during the Cambrian.
NATURE COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Sari Goldstein Ferber, Aron Weller, Michal Ben-Shachar, Gil Klinger, Ronny Geva
Summary: This paper proposes a theory on the ontogenetic-neurobiological basis of self-regulation, suggesting that it is a complex mechanism starting from early brainstem development and progressing to cortical control. The paper discusses the synchronous reactivity between the sympathetic and parasympathetic systems, as well as the development of cardiovascular and white matter, in creating self-regulatory functions. It also proposes hypotheses for further investigation of the clock circuitry and its associations with other biological clocks.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)