Results 1 to 10 of about 4,192 (190)

Early Tremadocian cephalopods from Santa Rosita Formation in NW Argentina: the oldest record for South America [PDF]

Acta Palaeontologica Polonica, 2023
We describe early Tremadocian (Kainella meridionalis Biozone) cephalopods from the Cordillera Oriental, Jujuy, NW Argentina. They consist of numerous small specimens collected at the Quebrada de Arenal, Trancas section, near the town of Tilcara, in the
MARCELA CICHOWOLSKI, N. EMILIO VACCARI, ALEXANDER POHLE, DANIEL A. MORÓN ALFONSO, ROMAIN VAUCHER, BEATRIZ G. WAISFELD   +5 more
doaj   +1 more source

Systematics, morphology, and appendages of an Early Ordovician pilekiine trilobite Anacheirurus from Fezouata Shale and the early diversification of Cheiruridae [PDF]

Acta Palaeontologica Polonica, 2021
Pilekiines are the earliest diverging members of the successful trilobite family Cheiruridae. The pilekiine genus Anacheirurus is characterized by sub-quadratic to sub-oval glabella, pitted genae, and a distinct trunk with elongated pleural spines in ...
FRANCESC PÉREZ-PERIS, LUKÁŠ LAIBL, MURIEL VIDAL, ALLISON C. DALEY   +3 more
doaj   +1 more source

EVENT STRATIGRAPHY AND CORRELATION PROBLEMS OF THE ORDOVICIAN STRATA OF GORNY ALTAI AND SALAIR

Геодинамика и тектонофизика, 2021
Study of the Ordovician sedimentary sequences of Gorny Altai and Salair has revealed lithological and paleontological features correlating with global sedimentary events:(1) The Acerocare Regressive Event (an initial event in the Early Tremadocian);(2 ...
N. V. Sennikov, O. T. Obut, E. V. Lykova, A. V. Timokhin, R. A. Khabibulina, T. A. Shcherbanenko   +5 more
doaj   +1 more source

Contrasting Early Ordovician assembly patterns highlight the complex initial stages of the Ordovician Radiation

Scientific Reports, 2022
The Early Ordovician is a key interval for our understanding of the evolution of life on Earth as it lays at the transition between the Cambrian Explosion and the Ordovician Radiation and because the fossil record of the late Cambrian is scarce.
Farid Saleh, Pauline Guenser, Corentin Gibert, Diego Balseiro, Fernanda Serra, Beatriz G. Waisfeld, Jonathan B. Antcliffe, Allison C. Daley, M. Gabriela Mángano, Luis A. Buatois, Xiaoya Ma, Daniel Vizcaïno, Bertrand Lefebvre   +12 more
doaj   +1 more source

Metal enrichment in lithologically complex black shales: a case study from the Tremadocian of NE Estonia [PDF]

Estonian Journal of Earth Sciences, 2021
Significantly elevated U, Mo, Zn and Pb contents characterize the Early Ordovician black shales in the Sillamäe area, NE Estonia. The presence of silty interlayers with sulphidic mineralization and authigenic carbonates suggests unique physicochemical ...
Rutt Hints, Siim Pajusaar, Kristjan Urtson, Merlin Liiv, Toivo Kallaste   +4 more
doaj   +1 more source

A Cambrian–Ordovician Terrestrialization of Arachnids [PDF]

Frontiers in Genetics, 2020
Understanding the temporal context of terrestrialization in chelicerates depends on whether terrestrial groups, the traditional Arachnida, have a single origin and whether or not horseshoe crabs are primitively or secondarily marine. Molecular dating on a phylogenomic tree that recovers arachnid monophyly, constrained by 27 rigorously vetted fossil ...
Jesus Lozano-Fernandez, Jesus Lozano-Fernandez, Alastair R. Tanner, Mark N. Puttick, Jakob Vinther, Jakob Vinther, Gregory D. Edgecombe, Davide Pisani, Davide Pisani   +8 more
openaire   +5 more sources

A new species of the problematic organism Webbyites from the Early Ordovician Fezouata Biota of Morocco [PDF]

Estonian Journal of Earth Sciences, 2023
The problematic colonial organism Webbyites has previously been considered to be a hydroid (phylum Cnidaria). In this paper, we describe a new species, Webbyites felix sp. nov., from the Early Ordovician Fezouata Konservat-Lagerstätte of Morocco.
Lucy A. Muir, Juan Carlos Gutiérrez-Marco   +1 more
doaj   +1 more source

New contributions to the Ordovician biostratigraphy of the Western Precordillera, Argentina [PDF]

Estonian Journal of Earth Sciences, 2023
Upper Ordovician graptolites and conodonts are recorded from the Yerba Loca Formation in two sections, in the El Toro and Las Viudas creeks, from the El Tigre Range in the Western Precordillera of San Juan Province, Argentina. A collection of graptolites
Fernando E. Lopez, Gladys Ortega, Guillermo L. Albanesi, Aldo L. Banchig   +3 more
doaj   +1 more source

Integration of Darriwilian (Middle Ordovician) δ13Corg chemostratigraphy with graptolite biostratigraphy in the classical Röstånga area in northwestern Scania (southern Sweden) [PDF]

Estonian Journal of Earth Sciences, 2020
The largely covered Middle Ordovician succession in the classic geological Röstånga area in northwestern Scania has not been studied for some 80 years.
Stig M. Bergström, Per Ahlberg, Jörg Maletz, Frans Lundberg, Michael M. Joachimski   +4 more
doaj   +1 more source

Shale lithofacies types and reservoir characteristics from Ordovician Wufeng Formation to the first sub-member of the first member of Silurian Longmaxi Formation, northeast Zhaotong area

Shiyou shiyan dizhi, 2023
Shale lithofacies has an important influence on shale reservoirs. It controls the hydrocarbon generation capacity, storage performance and fracturing performance of shale to a certain extent.
Guanbao REN, Lei CHEN, Yubing JI, Qingsong CHENG   +3 more
doaj   +1 more source