Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Steppe development and mammalian adaptation in the middle Miocene, North Junggar Basin, Central Asia","authors":"Jian Wang ,&nbsp;Xinying Zhou ,&nbsp;Shiqi Wang ,&nbsp;Jie Ye ,&nbsp;Junchi Liu ,&nbsp;Wenyu Wu ,&nbsp;Yan Wu ,&nbsp;Keliang Zhao ,&nbsp;Yan Zheng ,&nbsp;Hermann Behling ,&nbsp;Xiaoqiang Li","doi":"10.1016/j.palaeo.2024.112634","DOIUrl":"10.1016/j.palaeo.2024.112634","url":null,"abstract":"<div><div>The Central Asian (CA) steppe ecosystem and its fauna experienced a marked transition during the Miocene Climatic Optimum (MCO), though the specific process and dynamics remain elusive. We selected the Duolebulejin (DLB) section within the Junggar Basin to reconstruct vegetation and climate changes, using proxies such as particle size, mammalian fossils, and previously reported data including pollen, δ¹³C_TOC, and magnetic susceptibility. The results reveal three distinct phases of transformation in regional vegetation and fauna from 18.8 to 13.2 Ma. During the pre-MCO (18.8–17.0 Ma), the landscape was dominated by desert scrubland, primarily inhabited by rodents. The MCO (17.0–14.5 Ma) witnessed a shift towards steppe vegetation, initially with herbaceous taxa followed by the establishment of C₄ plants, alongside a diversity of large mammals adapted to open habitats. This suggests the emergence of savanna-like woodland steppes. In the post-MCO (14.5–13.2 Ma), the region transitioned to a dry steppe, accompanied by a decline in animal populations, although a significant proportion of species remained adapted to steppe environments. These findings underscore a co-evolutionary relationship between the development of steppe ecosystems and mammalian adaptations, driven by global MCO warming and subsequent cooling, with regional hydroclimatic changes acting as a modulating factor. The steppe-fauna biome emerged in the Junggar Basin during the MCO warming, with mechanisms resembling those of tropical savannas in the late Miocene. These insights enhance our understanding of early steppe ecosystem evolution through past warming periods, shedding light on the pathways to modern steppe formation.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112634"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Episodic marine anoxia, primary production, and weathering controls on carbon‑sulfur cycling in the Early Cambrian Yangtze Block","authors":"Moïse Luemba ,&nbsp;Zhonghong Chen ,&nbsp;Keyu Liu ,&nbsp;Zhi Chai ,&nbsp;Yong Chen ,&nbsp;Raphael Matamba ,&nbsp;Munezero Ntibahanana","doi":"10.1016/j.palaeo.2024.112632","DOIUrl":"10.1016/j.palaeo.2024.112632","url":null,"abstract":"<div><div>The Early Cambrian Period has received significant attention for decades owing to its geological records of unprecedented skeletal fossils, suggesting a major bio-event known as “the Cambrian Explosion.” Notwithstanding, related primary production and marine redox variation with respect to evolution of biota remain elusive. These factors are intimately linked to marine carbon‑sulfur cycling, promoting an extensive use of related isotopes (e.g., <em>δ</em>^<em>13</em><em>C</em> and <em>δ</em>^<em>34</em><em>S</em>) as paleoenvironmental proxies. Nevertheless, bulk-rock <em>δ</em>^<em>34</em><em>S</em> and <em>δ</em>^<em>13</em><em>C</em> may reflect multigenerational ³⁴S/³²S and ¹³C/¹²C isotopic fractionations. Herein, we analyzed drill cores from continuous depth profiles in the recently discovered Qingchuan-Ziyang-Yibin intrashelf basin for <em>δ</em>^<em>34</em><em>S</em> of sedimentary sulfate (<em>δ</em>^<em>34</em><em>S</em>_{<em>sulf</em>}), <em>δ</em>^<em>13</em><em>C</em> of carbonates (<em>δ</em>^<em>13</em><em>C</em>_{<em>carb</em>}), and bulk-rock elements. We find that highly positive (+23.60 ‰ to +29.90 ‰) and negative (as low as −12 ‰) <em>δ</em>^<em>34</em><em>S</em>_{<em>sulf</em>} V-CDT are associated with samples exhibiting low and high detrital inputs, respectively. In contrast, total sulfur and <em>δ</em>^<em>13</em><em>C</em>_{<em>carb</em>} V-PDB show no relationship with terrigenous materials. Enrichment factors of molybdenum (Mo_EF) and uranium (U_EF), biogenic contents of nickel (Ni_bio) and copper (Cu_bio), as well as total organic carbon (TOC), are all widely distributed among the samples. Integration of these findings with existing data from shallow to deep marine environments in the Yangtze Block, supports the following conclusions: (1) Five episodes of widespread marine anoxia coincide with extensive primary production. (2) Inputs of terrigenous materials promote ³²S-enriched sulfate, which adds to subsequent biochemical fractionations, resulting in generally complex pathways for <em>δ</em>^<em>34</em><em>S</em> of pyrite. (3) Terrigenous nutrients were critical to extensive marine primary production.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112632"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental changes in East-Central Europe from a Middle to Late Holocene Romanian cave sediment record","authors":"Bogdan P. Onac ,&nbsp;Angelica Feurdean ,&nbsp;Aritina Haliuc ,&nbsp;Simon M. Hutchinson ,&nbsp;Ferenc L. Forray ,&nbsp;Andrea Demjén ,&nbsp;Adriana Vulpoi ,&nbsp;Răzvan Dumbravă ,&nbsp;Adrienn Lőrincz ,&nbsp;Călin Ghemiș ,&nbsp;Augustin Nae ,&nbsp;Viorel T. Lascu ,&nbsp;Florin Gogâltan ,&nbsp;Ioana N. Meleg","doi":"10.1016/j.palaeo.2024.112672","DOIUrl":"10.1016/j.palaeo.2024.112672","url":null,"abstract":"<div><div>Caves are sensitive to hydrological processes including sediment transport associated with changes in external climatic conditions. When located in the proximity of prehistoric settlements, cave sediments can provide details about human activities and help to elucidate the paleoenvironment. Here, we present a comprehensive analysis of lithological, geochemical, magnetic, organic matter, non-pollen palynomorphs, and charcoal data from sediment in Ciur Izbuc Cave, revealing significant paleoenvironmental and hydrodynamic changes over the past 6500 years. The first phase (6500–3500 calibrated years BP; cal BP) depicts a dynamic system with constant surface-subsurface connections, moderate-to-high erosion, and low-to-moderate sediment accumulation rates. The low charcoal levels during this phase indicate limited human impact. The second phase (3500–1400 cal BP) features contrasting depositional environments; the initial interval shows low accumulation under reduced water flow, reflective of a stable late mid-Holocene climate, while the subsequent interval reveals an abrupt shift to wetter conditions, characterized by runoff-derived minerogenic sediments. This period coincides with increased human impacts, including fire activity and land-use changes since the late Bronze Age. The third phase (1400–100 cal BP) exhibits complex hydrological dynamics, with sporadic, intense erosion linked to short-term climatic shifts. Increased charcoal concentrations and the presence of fungi indicate persistent human activity, intensifying after 300 cal BP. Our findings underscore the complex relationship between climate events, humans, and sediment dynamics in the Ciur Izbuc Cave, highlighting the utility of a multi-proxy approach in reconstructing past environmental changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112672"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation ages and environmental conditions of paleo-periglacial involutions in the Yellow River source area, northeastern Tibetan Plateau","authors":"Yao Jin ,&nbsp;Yuzhu Zhang ,&nbsp;Ninglian Wang ,&nbsp;Chun Chang Huang ,&nbsp;Jiangli Pang ,&nbsp;Yan Zhu ,&nbsp;Longsheng Wang ,&nbsp;Mengting Li ,&nbsp;Sikai Wang ,&nbsp;Pengpeng Cao ,&nbsp;Qili Xiao ,&nbsp;Jinpeng Zhou ,&nbsp;Xiaoling Huang ,&nbsp;Zhenyang Wang","doi":"10.1016/j.palaeo.2024.112659","DOIUrl":"10.1016/j.palaeo.2024.112659","url":null,"abstract":"<div><div>The northeastern (NE) Tibetan Plateau is located in the transitional zone between seasonally frozen soil and permafrost. This region exhibits an increased sensitivity to global changes and is an important area for investigating permafrost development, climate change, and environmental evolution. Through extensive field investigations, typical paleo-periglacial involutions (cryoturbation structures) were identified in the Yellow River source area on the NE Tibetan Plateau. Based on this newly discovered profile and integrating findings from previous studies in the region, we present a comprehensive analysis of paleo-periglacial involutions, focusing on morphological characteristics, chronostratigraphy, and environmental conditions. Our results show that: (1) folds correspond to the typical types of periglacial involutions, including individual undulating, large/small symmetrical undulating, pocket, and dyke; (2) two phases of paleo-periglacial involution events, occurring at 27.47 ± 3.57 to 14.66 ± 0.54 ka and 13.08 ± 0.88 to 11.06 ± 0.88 ka and corresponding to the Last Glacial Maximum and the Younger Dryas, respectively; (3) formation environments of periglacial involutions involve the interplay of climate, geomorphology, and lithology. This study holds paramount significance in enhancing the understanding of periglacial phenomena on the Tibetan Plateau. It also contributes substantially to elucidating the developmental patterns of paleo-periglacial involutions and their consequential impact on global environmental changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112659"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrogenic carbon records of Holocene fire dynamics in the Yellow River Basin: Climate change and human activity forcing","authors":"Chuchu Zhang ,&nbsp;Yifei Qiu ,&nbsp;Chenglong Wang ,&nbsp;Qinya Fan ,&nbsp;Ziyue Feng ,&nbsp;Xinqing Zou","doi":"10.1016/j.palaeo.2024.112626","DOIUrl":"10.1016/j.palaeo.2024.112626","url":null,"abstract":"<div><div>Fire is a crucial component of Earth's ecosystems, with important environmental and socioeconomic implications. In this paper, we analyze black carbon and polycyclic aromatic hydrocarbons in a sediment core (YS-A) from the South Yellow Sea to investigate the driving forces of fire activity in the Yellow River Basin since 7.0 ka BP, when sea level stabilized and the modern pattern of ocean circulation system established. Our results indicate that fire activity gradually increased between 7.0 and 4.0 ka BP, reaching its highest level around 4.0–3.5 ka BP, and weakened between 3.5 and 0.5 ka BP, before rapidly increasing again after 0.5 ka BP. Climate change was found to be the dominant factor influencing fire history, with drier climatic conditions promoting fire activity during 7.0–4.0 ka BP, but suppressing it after 4.0 ka BP. This varied response of fire to climatic conditions is linked to the complex interaction between rainfall, vegetation cover, and fuel availability. Human activity is also shown to exert a complex impact, with some activities, such as deforestation, reducing vegetation cover and limiting fire activity over Late Holocene timescales, while other factors, such as coal burning, increasing high-temperature combustion since 0.5 ka BP. Furthermore, our findings suggest that fire activity has significantly influenced carbon sequestration in marine sediments, leading to an increase in the burial of refractory carbon from approximately 12 % to 18 % between 7.0 and 3.5 ka BP, and a higher proportion of terrestrial organic matter.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112626"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silurian–Devonian boundary in Northern Xinjiang, NW China","authors":"Jiayi Yin ,&nbsp;Ladislav Slavík ,&nbsp;Ruiwen Zong ,&nbsp;Yiming Gong","doi":"10.1016/j.palaeo.2024.112636","DOIUrl":"10.1016/j.palaeo.2024.112636","url":null,"abstract":"<div><div>During the Silurian–Devonian Boundary (SDB) interval, in contrast to the predominantly carbonate facies observed in Europe and North America, China was composed of several plates/terranes dominated by clastic and pyroclastic rocks. Continuous sections across the SDB have been only sporadically reported from the orogenic belts and southwestern margin of South China. In many regions or sections in China, the identification of the SDB is based solely on fossil assemblages or non-index fossils, which results in only a rough approximation of the position of the boundary. This study focuses on the Junggar area in the Central Asian Orogenic Belt, characterized by pyroclastic rocks and scarcity of fossils compared to regions with carbonate dominated successions. This paper summarizes previous research findings and discusses the SDB in northern Xinjiang, China, integrating new data on Devonian conodont <em>Caudicriodus hesperius</em>, the presence of benthic organisms represented by encrinurid trilobites and crinoids, and the occurrence of late Silurian graptolites, along with the first organic carbon isotope curve around the SDB for the Central Asian Orogenic Belt, and provided crucial evidence for the recognition of the SDB in the orogenic belt area of China, consindering the SDB in Northern Xinjiang is located within the Utubulag Formation in the western Junggar and the presence of the SDB in the Kaokesaiergai Formation of the eastern Junggar has also been confirmed. The age of the corresponding strata: Utubulag, Manger, Kaokesaiergai formations are revised, and a more detailed description of the classic sections of the SDB in northern Xinjiang is provided. The new fossil and geochemical data serve as basis for recognition of the Silurian–Devonian boundary in northern Xinjiang, and also contribute to a more comprehensive understanding of paleoenvironmental events at the Silurian–Devonian transition in the northern hemisphere and the orogenic belt areas.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112636"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating high-resolution Sr/Ca and ultrastructural analyses of the Tridacna squamosa shell to reconstruct sub-daily seawater temperature variation","authors":"Cornélia Brosset ,&nbsp;Chengcheng Liu ,&nbsp;Haotian Yang ,&nbsp;Hong Yan ,&nbsp;Bernd R. Schöne","doi":"10.1016/j.palaeo.2024.112663","DOIUrl":"10.1016/j.palaeo.2024.112663","url":null,"abstract":"<div><div>Modern and fossil bivalves record environmental variability in their shells in the form of chemical and ultrastructural properties as well as changes in growth rate. These proxy data can be placed in precise temporal context based on growth pattern analysis. Some species such as tridacnids grow particularly fast providing unique insights into environmental changes on the time scale of weather which opens new opportunities for paleoclimate research. Here, we assessed the potential use of the fluted giant clam (<em>Tridacna squamosa</em>) to reconstruct sub-daily sea surface temperature (SST) fluctuations from shell Sr/Ca ratios. Through a combined μm-scale analysis of shell Sr/Ca (NanoSIMS) and ultrastructure (SEM) it was possible to study shell material produced during daytime (growth increments) and nighttime (growth lines) separately. Unlike coarser resolution chemical analysis (LA-ICP-MS and ICP-OES), this approach revealed a significant positive correlation between SST and Sr/Ca during daytime (R² = 0.36, <em>p</em> &lt; 0.001). The correlation further increased when the NanoSIMS data of several consecutive daily increments were combined to match the sampling resolution of LA-ICP-MS and ICP-OES data, i.e., four days to two weeks (R² of up to 0.86, <em>p</em> &lt; 0.001). With an uncertainty of at least ± 1.5 °C, the applicability of the Sr/Ca thermometer remains limited considering that <em>T. squamosa</em> only occurs in ecosystems with minimal seasonal temperature amplitudes. Consistent daily Sr/Ca cycles were observed with local maxima at growth lines. This cyclic pattern was found even when the ultrastructure morphology varied or when the complex crossed-lamellar ultrastructure of the shell deviated from its typical configuration during extreme weather events. Therefore, Sr/Ca is likely not directly linked to the shell ultrastructure, but instead both properties are driven by underlying physiological factors.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112663"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chinese loess 10Be records for the Jaramillo polarity subchron","authors":"Weijian Zhou ,&nbsp;Yajuan Du ,&nbsp;Xiaolong Zhou ,&nbsp;Xianghui Kong ,&nbsp;Feng Xian ,&nbsp;Ling Tang ,&nbsp;Jie Zhou ,&nbsp;Guoqing Zhao ,&nbsp;Yunchong Fu ,&nbsp;Mengyu Zang","doi":"10.1016/j.palaeo.2024.112673","DOIUrl":"10.1016/j.palaeo.2024.112673","url":null,"abstract":"<div><div>The Jaramillo subchron is a significant mark for Mid-Pleistocene magnetostratigraphic division and dating. However, there is a lack of sufficient discussion on this boundary compared to the well-studied Brunhes/Matuyama geomagnetic reversal. A controversy remains over the precise position of the Jaramillo polarity subchron in the Chinese loess records, which has definitely hampered efforts to establish an accurate Chinese loess chronological framework and to correlate this with marine oxygen isotope records. Here, we present a high-resolution loess ¹⁰Be record to trace the Jaramillo polarity subchron in the Xifeng loess section from the Chinese Loess Plateau. The results indicate that the upper and lower boundaries of the Jaramillo occurred approximately at 994 ± 2 ka and 1072 ± 4 ka, corresponding to marine isotope stage 28 (i.e., MIS 28) and MIS 31, respectively. These new ¹⁰Be tracing results are consistent with that of marine sediment records, but they are younger than the ages obtained from paleomagnetic measurements of the same loess sediments by ∼ 12 ka and ∼ 16 ka, respectively. This suggests that a complex process of remanent magnetism acquisition took place in the loess. We propose that the primary remanence obtained during the Jaramillo polarity subchron was overprinted by later magnetic signals resulting in delayed geomagnetic polarity boundaries.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112673"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recognition of global carbon cycle perturbations in the Middle-Late Devonian New Albany Shale, south-central Indiana, U.S.A.: Deciphering local versus global influences on δ13CTOC patterns","authors":"James J. Zambito IV ,&nbsp;Victoria J. García Muro ,&nbsp;Claudia V. Rubinstein ,&nbsp;Annette C. Weldon","doi":"10.1016/j.palaeo.2024.112630","DOIUrl":"10.1016/j.palaeo.2024.112630","url":null,"abstract":"<div><div>Stable carbon isotope stratigraphy is an integral tool for identifying Devonian global events. Carbon-cycle perturbations (excursions) tend to have geologically short durations that aid in chemo- and chronostratigraphic correlation, but also provide insight as a proxy for extinction-causing anoxia (eutrophication) and climate change. In carbonate-dominated successions, carbonate carbon isotopes (δ¹³C_carb) provide a relatively reliable record of sea-water isotopic composition. However, since many Devonian global events are associated with anoxia, most geological records consist of black shale-dominated successions and therefore analysis of organic carbon isotopes (δ¹³C_TOC) may be the only method available for reconstructing the carbon cycle. Interpreting δ¹³C_TOC results is complicated, though, by the presence of marine and terrestrial sources of organic matter in many depositional settings; furthermore, differentiating these sources can be time-consuming and costly. This study utilizes δ¹³C_TOC, elemental detrital input and paleoredox proxies, and analysis of total organic carbon from the SDH-474 Core from Bartholomew County, Indiana, to recognize Devonian global events in the marine Middle-Late Devonian New Albany Shale. A novel schematic model is presented for integrating detrital input proxy data with δ¹³C_TOC patterns to decipher the role of local versus global carbon fluxes. Global carbon cycle perturbations are then identified within the context of conodont and palynomorph biostratigraphic data. In the SDH-474 Core, the Late Frasnian <em>semichatovae</em> Event and Late Frasnian into Early Famennian Lower and Upper Kellwasser events are recognized. The Early Frasnian Middlesex and/or Middle Frasnian Rhinestreet Events, as well as the Famennian Nehden, Condroz, and <em>annulata</em> events may also be represented in the core, but their identification is hindered by potential local terrestrial influence on the reconstructed δ¹³C_TOC record and/or a lack of a high-resolution global δ¹³C reference for these events.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112630"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New ecdysozoan fossil embryos from the basal Cambrian of China","authors":"Mingjin Liu ,&nbsp;Xiaofeng Xian ,&nbsp;Huaqiao Zhang ,&nbsp;Mats E. Eriksson ,&nbsp;Yunhuan Liu ,&nbsp;Tiequan Shao","doi":"10.1016/j.palaeo.2024.112635","DOIUrl":"10.1016/j.palaeo.2024.112635","url":null,"abstract":"<div><div>Invertebrate embryos have relatively low fossilization potential; however, when preserved, they can offer crucial insights into the evolutionary developmental biology of extinct animals. Here we report new exceptionally preserved fossil embryos from the early Fortunian (early Cambrian) of China, which are assigned to two new taxa, <em>Saccus xixiangensis</em> gen. et sp. nov. and <em>Saccus necopinus</em> gen. et sp. nov. All specimens are three-dimensionally phosphatized, akin to the Orsten-type preservation. The embryos are enclosed within a thin and smooth envelope ranging in diameter from 730 μm to 1 mm. The embryos have a bag-shaped body, a non-ciliated integument, radially arranged sclerites apically, and bilaterally arranged sclerites abapically, but lack any orifice, thus representing a developmental stage prior to the formation of a mouth or anus. The integument shows soft deformation, while the sclerites remain largely undeformed, suggesting that the sclerites are stiffer and likely cuticularized. The arrangement of the abapical sclerites imparts bilaterality, classifying these new embryos as bilaterians. Furthermore, the absence of cilia or cilium insertion sites and the presence of cuticularized sclerites suggest an ecdysozoan affinity. The relatively large embryo size indicates yolk-rich eggs, and the presence of cuticle implies that the embryos are in later embryonic stages, possibly close to hatching. In the absence of hatched specimens, it is inferred that these embryos undergo indirect development, hatching as lecithotrophic (yolk-feeding) larvae. In this case, the morphology of the juvenile and adult forms is uncertain due to metamorphosis during later growth. Alternatively, the embryos could undergo direct development, hatching as lecithotrophic juveniles, with both juveniles and adults potentially having a similar bag-shaped body without an introvert or paired limbs, closely reminiscent of <em>Saccorhytus</em>. This study expands our understanding of the morphological disparity and diversity of early Fortunian fossil embryos and ecdysozoans.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"659 ","pages":"Article 112635"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}