Terrestrialization in the Ordovician
Abstract This contribution reviews the evidence for terrestrial organisms during the Ordovician (microbial, land plant, fungal, animal) and for the nature of the terrestrial biota. The evidence regarding the origin and early diversification of land plants combines information from both fossils and living organisms.
Wellman, Charles+2 more
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Sheltered preservation in Ordovician trilobites [PDF]
Abstract. Articulated holaspid specimens of Placoparia Hawle and Corda, 1847 and Eoharpes Raymond, 1905 entombed inside cephalopod conchs and under the remains of large illaenid, asaphid, cyclopygid and dalmanitid trilobites from the Middle Ordovician Šárka Formation of the Prague Basin (Czech Republic) are described and discussed.
Fatka,Oldřich, Budil,Petr, Kraft,Petr
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Systematics, morphology, and appendages of an Early Ordovician pilekiine trilobite Anacheirurus from Fezouata Shale and the early diversification of Cheiruridae [PDF]
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+3 more
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The earliest cornulitid on the internal surface of the illaenid pygidium from the Middle Ordovician of Estonia [PDF]
The earliest cornulitid Cornulites sp. appears in the Darriwilian (Lasnamägi Regional Stage) of Estonia. Internal annulation is present in all Middle Ordovician cornulitids and could be a plesiomorphic character for the group.
Olev Vinn, Ursula Toom, Mare Isakar
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Stratigraphy and facies differences of the Middle Darriwilian Isotopic Carbon Excursion (MDICE) in Baltoscandia [PDF]
The Middle Darriwilian Isotopic Carbon Excursion (MDICE) is a global isotopic event described in sections from different palaeocontinents. Here we present new stable carbon isotopic data from carbonates of ten sections in different parts of the ...
Leho Ainsaar+5 more
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Metal enrichment in lithologically complex black shales: a case study from the Tremadocian of NE Estonia [PDF]
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+4 more
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Upper Ordovician hardgrounds – from localized surfaces to global biogeochemical events [PDF]
Upper Ordovician hardgrounds display a spectrum of complexity reflecting a range of local to global-scale processes. Hardgrounds are cemented seafloor surfaces typically marked by the presence of encrusting taxa and borings.
Timothy R. Paton+4 more
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Echinoderm Lagerstätten from high-latitude Gondwana – filling the gap in the Ordovician diversification of the phylum [PDF]
The phylum Echinodermata is a major component of marine ecosystems since the first appearance of echinoderms in the Cambrian. Like other metazoan phyla, echinoderms underwent two major evolutionary pulses in early Palaeozoic times: the Cambrian Explosion
Martina Nohejlová+4 more
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A Cambrian–Ordovician Terrestrialization of Arachnids [PDF]
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+8 more
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Changes in shelf phosphorus burial during the Hirnantian glaciation and its implications [PDF]
The Late Ordovician mass extinction occurred during an icehouse interval, accompanied by the glaciation of the supercontinent Gondwana, which was located at the South Pole at that time.
Johann Müller+4 more
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