Results 61 to 70 of about 874 (171)

Exceptionally preserved Cambrian trilobite digestive system revealed in 3D by synchrotron-radiation X-ray tomographic microscopy. [PDF]

PLoS ONE, 2012
The Cambrian 'Orsten' fauna comprises exceptionally preserved and phosphatised microscopic arthropods. The external morphology of these fossils is well known, but their internal soft-tissue anatomy has remained virtually unknown.
Mats E Eriksson, Fredrik Terfelt
doaj   +1 more source

Emplacement of Hybrid Continental‐Oceanic Arc Terranes Without Collision: The Devonian Calliope Arc (New England Orogen, Australia)

Tectonics, Volume 45, Issue 7, July 2026.
Abstract The accretion of allochthonous provinces, derived from oceanic plates, has traditionally been considered an important contributor to continental growth. However, increasing evidence shows that some oceanic terranes (e.g., island arcs) are not “exotic,” as suggested by the presence of continental‐derived sedimentary provenance.
Igor V. Gomes, Gideon Rosenbaum, Carlos A. Spier, Jack F. Ward, Luke A. Milan   +4 more
wiley   +1 more source

Confirmation of the impact origin of the Late Ordovician Tvären impact structure (southeast Sweden) and emplacement of impactites in a marine setting

Meteoritics &Planetary Science, Volume 61, Issue 7, Page 1188-1212, July 2026.
Abstract The Tvären structure in southeastern Sweden has been listed as a confirmed marine‐target impact structure for decades. However, to date, no measurements and/or indexed data of planar deformation features in quartz grains from the structure have been published or any other unequivocal evidence of impact.
Katarzyna J. Gajewska, Sanna Alwmark, Mikael Calner, Sylvain Richoz, Jens Ormö, Erik Sturkell, Carl Alwmark   +6 more
wiley   +1 more source

Bioestratigrafía a partir de trilobites de las Formaciones de Balang y “Tsinghsutung” (Serie Cámbrica 2, Piso 4) en el área de Balang, Jianhe, Guizhou, China meridional

Estudios Geologicos, 2019
Se está trabajando en las formaciones de Balang y “Tsinghsutung” para encontrar un candidato adecuado para la base de la Serie 2 del Cámbrico, Piso 4.
Y. Zhao, S. Peng, J. Yuan, J. Esteve, X. Yang, M. Wu, Z. Chen   +6 more
doaj   +1 more source

Revisiting the Hummeln structure, Sweden—A shallow marine Cambrian impact structure

Meteoritics &Planetary Science, Volume 61, Issue 7, Page 1213-1242, July 2026.
Abstract Hummeln is a simple impact structure located in south‐eastern Sweden. It is approximately 1.2 km in diameter and almost completely covered by a lake. Here, we present the first detailed investigation of impactites and mapping of the 164.25 m deep drill core Hummeln‐1 with a focus on impact metamorphism and the impact process.
S. Alwmark, J. Granbom, P. Ahlberg, M. Calner, S. Richoz, K. J. Gajewska, W. R. Hyde, K. Ljung, C. Alwmark   +8 more
wiley   +1 more source

Putative Analogs of Pyrite Suns Forming in Proglacial Alaska Mudflats

Journal of Geophysical Research: Biogeosciences, Volume 131, Issue 5, May 2026.
Abstract Disc‐shaped pyrite suns of the Pennsylvanian age Anna Shale are thought to have formed where pressure restricted pyrite crystal growth to a flattened disc shape during diagenesis at the Anna Shale and the underlying Herrin coal boundary.
Heather L. Fair, Trinity L. Hamilton, Jeff R. Havig   +2 more
wiley   +1 more source

Type Specimens of the Species of the Genus Papillicalymene (Arthropoda, Trilobita) from Ukraine Described by Leonid Konstantynenko

Zoodiversity
The article presents diagnoses and information on the type series of two trilobite species of the genus Papillicalymene Shirley, 1936: P. dnistroviana Konstantynenko, 2006 and P. sokoliana Konstantynenko, 2006 from the Ludlow (Upper Silurian) of Podillia
V. Dernov
doaj   +1 more source

Affinity in Concentric Circles (ACC): A Geometric Representation of Dendrogram and Interpretation

Journal of Biogeography, Volume 53, Issue 5, May 2026.
ABSTRACT Aim We introduce “Affinity in Concentric Circles” (ACC), a method that converts dendrograms to a geometric form using similarity scores to compare dendrograms and identify affinity change patterns. Location China for trilobites and global for nisusiid brachiopods.
Yeongju Oh, Jikhan Jung, Tae‐Yoon Park, Dong‐Chan Lee   +3 more
wiley   +1 more source

Moulting in Ordovician dalmanitoid and acastoid trilobites of the Prague Basin. Preliminary observation

Geologica Acta, 2005
A review of the supposed moulting positions of the Bohemian Ordovician dalmanitoid and acastoid trilobites is presented. Five main moulting positions are described, but some combinations of these are also widespread.
P. Budil, J. Bruthansová
doaj   +1 more source

Review of the Cambrian Stratigraphy of the Argentine Precordillera

Geologica Acta, 2003
The Cambrian rocks of the Argentine Precordillera are analyzed and updated providing a new stratigraphic interpretation. The lithostratigraphic assemblages provide evidence that the Precordilleran Cambrian Basin was a rimmed platform.
O. Bordonaro
doaj   +1 more source