This study reconstructs the fluvial dynamics of the Bras de Fer distributary in the Rhône Delta (France) during the Little Ice Age (LIA) in response to short-term climatic forcing. A multiproxy approach combining historical cartography, sedimentology, geochemistry, magnetic susceptibility, and hydrological archives reveals accelerated meander migration and extensive overbank accretion between the late seventeenth and early eighteenth centuries CE. Increased flood frequency, coinciding with positive phases of the Atlantic Multidecadal Oscillation (AMO+), promoted rapid lateral channel shifts and the formation of crevasse splay complexes along the outside bank of the Grande Ponche meander. The results demonstrate that, despite stable relative sea levels, deltaic morphology remained highly sensitive to decadal-scale climatic variability, highlighting the dominant role of hydrological extremes in shaping fluvial-deltaic environments of Rhône delta during the late LIA.

The Chalbi Desert, located in eastern Africa, is a significant but overlooked archive of the Pleistocene and Holocene periods that could add insight into investigations on human evolution. We revisited southeastern Chalbi Desert landforms between the towns of Kargi and Maikona to improve the chronostratigraphy and provide paleoenvironmental context. Direct U-series and electron spin resonance dating of various fossil teeth recovered from a deflated dune (Qzs) landform at the Farre locality return a mean age of ∼545 ka, which is compatible with biostratigraphic inferences. While this numerical age result should probably be regarded as mostly indicative given the existing uncertainty on the environmental dose rate evaluation, the data set available nevertheless strongly suggests a Middle Pleistocene age for at least some of the fauna. Sedimentology, luminescence, and 14C dating further suggest that this Qzs landform and its contents were modified by alluvial fan development and weathering during denudation in a proximal fan setting through the late Pleistocene into the Holocene. The Qzs landform currently experiences aeolian additions, erosion, and salt-affected soil development in an arid climate. Pedogenic carbonate isotope geochemistry suggests that deflated sand dunes were covered by woody grasslands during Marine Isotope Stage (MIS) 4 and 3 pluvials, consistent with nearby fan progradation constrained at >35 ka. The desert experienced increased hydrologic activity during late Pleistocene and African humid period pluvials, as evidenced by additional optically stimulated luminescence and 14C dating from fan, dune, and playa contexts. The last significant pluvial episode ended after 4.4 ± 0.3 cal ka BP, which coincides with the final regression of nearby Lake Turkana. This study extends the chronology of Quaternary sediments in the Chalbi Desert to the Middle Pleistocene and offers paleoenvironmental insights into the conditions experienced by Middle Stone Age tool users in the region.

Paleoecological reconstructions provide valuable insights into the impacts of environmental change on key functions of wetland ecosystems. Here, we integrate biological and sedimentological proxies to provide a baseline of vegetation and hydrological change since the Middle Holocene at a riparian marsh, with the goal of informing wetland restoration within a regional biodiversity hotspot in the Great Lakes coastal zone. Four stages of wetland development are identified, reflecting the combined impacts of Lake Erie fluctuations, fluvial processes, regional paleoclimate, and anthropogenic influence. Wetland establishment took place ∼6000 cal yr BP during a Lake Erie high stand, and pollen assemblages indicate that the site was initially a forested wetland. Subsequently, water levels remained elevated as a transition to an emergent marsh with silty, organic-rich sediments took place ∼5300 cal yr BP. Once water levels stabilized in the Late Holocene, a thicket swamp established in sandier sediments, suggesting closer proximity to the meandering channel. The intensification of European settlement from 1850 CE marked a major transition, resulting from disturbances caused by land clearance and hydrological alterations, including higher rates of sediment accretion, novel diatom communities, and increases in herbaceous vegetation. These paleoecological records demonstrate the importance of considering whole-watershed measures in restoration planning, including controls on mineral sediment influxes, maintenance of local water tables, and management of invasive species producing high biomass.

We present a Late Pleistocene paleoecological record from King Island in western Bass Strait, Tasmania, and compare this to existing records from the eastern Bass Strait islands to improve our understanding of the region’s paleoecology and paleoclimatology. Vegetation change across the region followed similar trajectories during the late glacial–Middle Holocene, characterized by homogeneous warming and wetting trends. Spatial divergence occurred during the Middle Holocene when sea level rose, and different drivers began influencing western and eastern Bass Strait islands. In eastern Bass Strait, Middle Holocene sea-level rise caused replacement of woodland by coastal heathland, while in the west, a drier period accompanied by fires transformed forests to forest–scrub. The comparative analysis suggests that Westerly driven climatic anti-phasing was pronounced at higher latitudes of Tasmania during the late glacial–Early Holocene. A combination of weak Leeuwin Current, positive Indian Ocean Dipole (IOD), and El Niño–Southern Oscillation (ENSO) intensification contributed to Middle Holocene aridity across Bass Strait. Strong Westerlies and negative IOD phases led to greater regionalization of rainfall across western Bass Strait during the Late Holocene, while ENSO intensification drove rainfall declines in eastern Bass Strait. These findings provide new insights into the complexity of Late Pleistocene environmental dynamics across southeast Australia.

Fossils and more recent remains of dead organisms serve as natural archives of Earth’s recent and ancient history. It is often the case that small or fragmented specimens, especially microvertebrate bones, go unstudied. Accurate identification of such remains to a specific taxonomic level can help address a wide range of questions spanning paleontology, paleoecology, zooarchaeology, ecology, conservation science, forensics, and biogeography. Geometric morphometrics demonstrates significant potential for identifying fragmented lizard fossils to at least the family level based on shape differentiation. Our proof-of-concept study using lizard maxillae of extant species within the Pacific Northwest, USA, accurately identified fragmented maxillae with as few as six comparative specimens per genus. These findings establish a framework for addressing taxonomic challenges in fragmented bone specimen identification for taxa whose curated comparative specimens are small in number and unequal in representation.

This paper presents the palaeoecological analysis of five latest Pleistocene (17,500–13,500 cal yr BP) Arctic ground squirrel (Urocitellus parryii) middens from three sites in the Klondike goldfields of central Yukon Territory. Plant and invertebrate macrofossil records were represented by 24 and 20 taxa, respectively, providing a record of the local environment and the earliest known occurrences in Yukon Territory for several taxa (e.g., the robber fly [Lasiopogon sp.] and marsh yellowcress [Rorippa cf. palustris]). The plant and invertebrate assemblages indicate the persistence of steppe-tundra to at least 13,680 cal yr BP by the preservation of taxa typically occupying dry sites, many of which remain components of grasslands and south-facing azonal steppe communities in present-day Yukon Territory. In the context of shrub expansion that is documented to have occurred by 14,000 cal yr BP in interior Alaska, we consider the taphonomic biases associated with Arctic ground squirrel middens that may lead to the lack of shrub macrofossils preserved at the sites. Our study provides an ecologically unique and chronologically constrained perspective on the local persistence of steppe-tundra in easternmost Beringia despite the regional expansion of shrubs.

Identifying the causative agents of modified bone surfaces can be challenging, particularly in terrestrial systems where numerous biotic and abiotic factors can produce grooves, divots, and striae. This contribution focusses on fossil vertebrates in the Làng Tráng cave system in Vietnam, which preserves a diverse assemblage of middle Pleistocene mammals, and discusses criteria that can identify the agents responsible for the accumulation and degradation of the fossil accumulation. The Làng Tráng assemblage includes some postcranial elements and rare mandibles and skulls, but is dominated by isolated teeth and bones, particularly those of mid-sized (7–250 kg body weight) mammals. Rare long bone shafts exhibit grooves with U-shaped profiles attributable to the ichnotaxon Machichnus bohemicus. In contrast, flat-bottomed grooves attributable to M. multilineatus are exceptionally abundant. The size and shape of these traces are consistent with gnawing by moderate-sized to porcupines such as Atherurus macrourus and Hystrix kiangsenensis, both of which are represented in the Làng Tráng fauna. Porcupines are common contributors to cave faunas in Southeast Asia. The roots of most teeth exhibit moderate to severe biogenic modification, which resulted in common planar facets in some cases and reduction of the root bone to pyramidal wedges in others. The Làng Tráng cave system is unusual in that porcupines did not just contribute to the fauna; they were the dominant taphonomic factor in the accumulation and subsequent biogenic alteration/degradation of bone in these caves. Faceted and wedged roots are herein proposed as diagnostic attributes of porcupine-generated vertebrate bone accumulations.

Understanding biotic responses to environmental changes will help identify extinction risks and direct conservation efforts to mitigate negative effects associated with anthropogenic-induced environmental changes. Here we use the Quaternary fossil record of mole salamanders (Ambystoma) from the southwestern United States and northern Mexico to reveal geographic patterns of extirpation since the Pleistocene. Ambystoma are known to have previously inhabited regions of central Texas on the Edwards Plateau; however, they are largely absent from the region today. We used a well-dated fossil record of Ambystoma from Hall’s Cave combined with other fossil sites in the region to deduce why Ambystoma was ultimately extirpated from the Edwards Plateau and to test hypotheses related to temperature-driven body-size changes in line with the temperature–size rule. We propose that Ambystoma was likely extirpated from the region due to changing temperature and precipitation regimes that caused increased mortality and disruptions to breeding and larval development. We found some support for decreased body size in Ambystoma with increased temperature during the late Pleistocene, suggesting that body size may be an important feature to monitor in modern populations of Ambystoma as salamanders become subjected to increasingly hotter temperatures in the coming decades.

Rhizoliths, cylindrical concretions formed primarily by CaCO3 accumulation around plant roots, serve as valuable indicators of past environmental conditions, including hydrology, redox dynamics, and carbon cycling. Despite growing interest in paleo-reconstructions, the lack of quantitative studies on formation mechanisms complicates interpretation. We present “RhizoCalc”, the first mechanistic model (deployed in HYDRUS-1D) computing rhizolith formation in CaCO3-containing loess soils, integrating water fluxes, root water uptake, and (Ca)-carbonate chemistry to simulate conditions under which rhizoliths develop. Hydraulic fluxes drive Ca2+ transport (0.13–1 mmol/L) toward the rhizosphere, governed by root water uptake under low (ETo = 0.03 cm/d) and high (ETo = 1 cm/d) flow rates at optimal (ho = –100 cm) and intermediate (ho = –1000 cm) moisture conditions. The simulations show that hydraulic constraints and calcite-induced jamming of the porous medium are key inhibitors of rhizolith growth, distinguishing physical limitations from biogeochemical feedbacks in the rhizosphere. On top of this, our work reveals root encasement and reliquary varieties, linking their physical and biogeochemical mechanisms to rhizolith transformations and offering insights into paleosol hydrology and redox dynamics. Under intermediate soil-water conditions with 1 mmol/L Ca2+, concentric rhizoliths with 0.2–3 cm radii form chrono-sequentially over 1.5–150 years. Each layer preserves CaCO3 constituents (δ18O, δ13C, 44Ca, 46Ca, 48Ca), root-derived biomarkers (e.g., lignin), and clumped isotopes (Δ47), preserving environmental signatures across time into the future. Therefore, this framework conceptualizes each rhizolith as a ‘time-capsule’ with each successive CaCO3 layer encapsulating a snapshot of vital environmental proxies, providing a window into otherwise inaccessible historic ecosystem dynamics. Refining reconstructions of Earth’s paleoclimatic history requires cross-sectional isolation of concentric layers in well-preserved rhizoliths, capturing distinct isotopic bands and their stratigraphy.

This study examines tephra layers from lacustrine sediment cores collected in Patagonian Andean Range, correlating them with volcanic sources from the southern segment of the Southern Volcanic Zone (SVZ). Ten distinct tephra layers, spanning approximately the last 2000 yr, were identified across four cores from Lakes Rivadavia, La Zeta, Brychan, and Theobald, from ∼42°S to 44°S. Mostly geochemical and mineralogical analyses of tephra components (pumice, glass shards, scoria) reveal that the Chaitén, Michinmahuida, and Huequi volcanoes are the main sources of tephra in the region. Identified eruptions include four from Chaitén (ca. 2008 CE, ca. twelfth, ca. eighth, and fourth to fifth centuries), two from Huequi (beginning of the nineteenth and, possibly, fourteenth centuries), and four from Michinmahuida (ca. seventeenth to eighteenth, thirteenth, eighth, and ca. second centuries). Four of these tephra layers also have potential as isochronous marker beds in the region, allowing a preliminary reconstruction of their regional dispersal patterns. Some tephras may represent previously undocumented or scarcely documented eruptions. These findings suggest that the eruptive frequency in the southern SVZ has been underestimated, emphasizing the need for further research to expand the eruptive history and more accurately assess the volcanic hazards associated with this region.

Understanding the spatiotemporal variability of global summer monsoons and the factors controlling them is essential for testing and predicting their future changes under the anticipated global warming. Here, we reconstructed a series of East Asian summer monsoon (EASM) patterns over South Korea. Based on radiocarbon dates, grain size, carbon/sulfur (C/S) ratios, and high-resolution X-ray fluorescence core scanning (XRF-CS) data (e.g., Ti/Al and Zr/Al ratios) from a paleo-bay site in Hadong area, southern Korea, we investigated the multi-decadal- to centennial-scale variation in the terrestrial element inputs as a proxy for the EASM rainfall during the period from 8600 to 7800 cal yr BP and compared previous results from the Buan area, western coast of Korea, to test possible synchronous local-scale hydroclimate change. We also explored global teleconnections among EASM over Korea, the Indian summer monsoon (ISM), and the movement of the Intertropical Convergence Zone (ITCZ). We found that the EASM variability was positively correlated with that of the ISM through latitudinal shifts of the ITCZ. High-latitude cooling climates, including the 8.2 ka cooling event, were also directly connected to the weakened EASM via the intensified winter monsoon and southward shift of the westerly jet position over the Tibetan Plateau. To predict future changes in summer rainfall, synchronized changes in the global summer precipitation should be considered in terms of ITCZ and high-latitude climate change, including westerly jet shifts over Asian regions.