Low oxygen but dynamic marine redox conditions permitted the Cambrian Radiation

Science Advances, Год журнала: 2025, Номер 11(4)

Опубликована: Янв. 24, 2025

Whether metazoan diversification during the Cambrian Radiation was driven by increased marine oxygenation remains highly debated. Repeated global oceanic events have been inferred this interval, but degree of shallow and its relationship to biodiversification clade appearance remain uncertain. To resolve this, we interrogate an interval from ~527 519 Ma, encompassing multiple proposed events. We integrate spatial temporal distribution water, in situ reef metazoans, trilobites, with high-resolution multi-proxy redox data through biodiverse Siberian Platform. document primarily dysoxic water column conditions, suggesting that early including motile skeletal benthos, had low oxygen demands. further coincident positive carbon isotope excursions led modestly elevated levels. These correspond regional increases species richness habitat expansion mainly endemic species, offering a potentially globally applicable model for Radiation.

Язык: Английский

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The Quanjishan Charnia assemblage from the northern Qaidam Basin, Tibetan Plateau, and implications for palaeoecology and taphonomy of Ediacaran fronds

Palaeogeography Palaeoclimatology Palaeoecology, Год журнала: 2025, Номер unknown, С. 112816 - 112816

Опубликована: Фев. 1, 2025

Язык: Английский

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Detrital zircons from Cambrian rocks of western Laurentia define two episodes of Rodinian rift-related magmatism

Geoscience Frontiers, Год журнала: 2025, Номер unknown, С. 102007 - 102007

Опубликована: Янв. 1, 2025

Язык: Английский

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Controls on the termination of the massive chert system in the Ediacaran-Cambrian Liuchapo Formation, South China

Precambrian Research, Год журнала: 2025, Номер 419, С. 107729 - 107729

Опубликована: Фев. 14, 2025

Язык: Английский

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Oceanic redox condition and the evolution of Ediacaran life: Evidence from nitrogen isotopes and biogenic silica in the Yangtze Block, South China

Palaeogeography Palaeoclimatology Palaeoecology, Год журнала: 2025, Номер unknown, С. 112903 - 112903

Опубликована: Март 1, 2025

Язык: Английский

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Origins and Alteration of Ediacaran Carbonates Recording the Shuram Excursion in Oman

Geochemistry Geophysics Geosystems, Год журнала: 2025, Номер 26(5)

Опубликована: Май 1, 2025

Abstract The Shuram excursion is the largest known negative carbon isotope in Earth's history. Recognized globally, it follows Ediacaran Gaskiers glaciation and precedes a marked increase diversity complexity of earliest macroscopic multicellular organisms fossil record. A key question whether this reflects primary perturbation to cycle, which would provide crucial insights into environmental conditions shaping animals, or largely an artifact later diagenetic alteration. To evaluate extent diagenesis these rocks constrain how much signal, we investigate sedimentology geochemistry carbonate strata Oman using variety techniques spanning multiple spatial temporal scales. Our multi‐faceted analysis identifies characterizes four modes alteration, with sediment‐buffered authigenic precipitation as dominant processes. However, degree alteration insufficient account for range marine sedimentologic geochemical trends across excursion. This suggests that, even evidence diagenesis, preserve measurable record changing both terrestrial environments, offering unique systems during pivotal time early animal evolution.

Язык: Английский

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The evolution of reproduction in Ediacaran–Cambrian metazoans

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2025, Номер unknown

Опубликована: Май 15, 2025

ABSTRACT The evolution of reproductive style is a fundamental aspect metazoan life history but has not been explored holistically through the Ediacaran–Cambrian rise metazoans. Recent molecular clock analyses based on only unequivocal fossil calibrations suggest that Porifera were present by at least 590 million years ago (Ma), all major eumetazoan clades originated in mid–late Ediacaran, and bilaterians probably late Ediacaran. An alternating pelagic larval (potentially for dispersal) benthic adult cycle appears to be an ancestral feature A compilation inferred styles from record reveals low‐competition, deep‐water communities Ediacaran Avalon macrofossil assemblage ( ca . 575 560 Ma) had current‐borne sexually produced with both local (non‐planktotrophic, no feeding) more widespread (planktotrophic, dispersal followed vegetative growth. By Ma, White Sea shallow settings show dense aggregations, which often dominated single populations episodic spatfalls. Some taxa may potential philopatry. 550 biomineralization colonisation marine carbonate settings, ability encrust hard substrates, create multiple branches via budding, rudimentary mutual attachment clones, first appear. dominant apparent mode reproduction throughout was therefore larvae asexual reproduction, either fragmentation or fission. In these where biotic interactions limited, this enabled newly available soft substrates rapid Early Cambrian showed increased endemism, enhanced trophic macropredation. early Fortunian stage 535 Ma), gonochorism (separate sexes) have priapulid worms. During Stage 2 532 internal fertilisation appeared molluscs planktotrophy did appear until latest Cambrian/early Ordovician. Mutual diverse skeletal became common, particularly within reefs. Evidence egg brooding parental care arthropods 3 518 Ma). While independently acquired, overall pattern suggests shift higher fecundity quality offspring some groups during Radiation, driven increasing interactions, including

Язык: Английский

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Revising the lithostratigraphic framework of the Ediacaran succession of the Anti-Atlas belt: correlation across the Cadomian domain of the West African Craton

Journal of African Earth Sciences, Год журнала: 2025, Номер unknown, С. 105696 - 105696

Опубликована: Май 1, 2025

Язык: Английский

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RIBBON-LIKE COMPRESSION FOSSILS FROM THE LATE EDIACARAN ESMERALDA MEMBER OF THE DEEP SPRING FORMATION AT MOUNT DUNFEE, NEVADA, USA

Palaios, Год журнала: 2025, Номер 40(5), С. 131 - 140

Опубликована: Май 20, 2025

Abstract We describe > 200 ribbon-like macroscopic fossils from terminal Ediacaran strata at Mount Dunfee, Nevada, USA ∼ 115 m below the local placement of Ediacaran–Cambrian boundary. They are preserved as casts and molds, composed Fe-oxides Fe-rich aluminosilicates in an aluminosilicate clay matrix. Measurements 50 specimens provide a fossil size range 0.22–0.74 mm-wide 0.1–75.0 mm-long. Some evidence original flexibility appear to be fragmented, consistent with soft body preservation. therefore interpreted fossils, rather than trace fossils. Given this interpretation, we suggest that fossils’ morphologies them being members problematicum Vendotaenia, which have not been previously reported within southern Great Basin. The phylogenetic affinity vendotaenids is unresolved, but they commonly form eukaryotic macroalgae. This report firmly establishes on Laurentia, broadening their known paleogeographic during end-Ediacaran Period. Additionally, morphology described here supports notion that, although many paleocontinents globally, there was low macroalgal diversity end

Язык: Английский

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Foundational uncertainties in terminal Ediacaran chronostratigraphy revealed by high-precision zircon U Pb geochronology of the Nama Group, Namibia

Earth-Science Reviews, Год журнала: 2025, Номер unknown, С. 105169 - 105169

Опубликована: Май 1, 2025

Язык: Английский

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