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Associated with ongoing global warming, prolonged periods of negative mass balance affect even Alpine glaciers in high summit regions, which are also prime candidates for paleoclimate-related ice core studies. This greatly complicates the already challenging task of establishing an age-depth relationship where now both, the age at depth and at the surface is an unknown. Radiometric ice dating methods are an important key to tackle this challenge. This study presents a comprehensive age-depth profile of the summit glacier of Weißseespitze (WSS, 3500 m a.s.l.) in the Austrian Alps, utilizing a combination of radiometric dating methods - .sup.39 Ar and .sup.14 C. Ice cores from drilling campaigns conducted in 2019, 2023, and 2024 were analyzed to overcome challenges posed by extensive ice loss and surface melting that limit traditional dating techniques. All .sup.39 Ar samples were measured using atom trap trace analysis (ATTA). Surface mass balance (SMB) data since 2019 were used to align core depths across years, and all samples were referenced to height above bedrock to standardize comparisons.

The rarity of Late Pleistocene hominin remains from Insular Southeast Asia (ISEA) has hampered our ability to understand a crucial episode of human evolutionary history, namely, the global dispersal of Homo sapiens from Africa. Moreover, recent discoveries indicate a surprising level of taxic diversity during this time with at least two species-H. floresiensis and H. luzonensis-endemic to the region when H. sapiens first arrived. A third hominin dubbed the 'Denisovans' is shown from DNA evidence to have interbred with the ancestors of contemporary Indigenous populations across ISEA, New Guinea and Australia. Yet, the Denisovans have not been identified from the fossil record of the area despite recent breakthroughs in this regard on mainland East Asia. New excavations by our team at the Trader's Cave in the Niah National Park ('Niah Caves'), northern Borneo, have yielded an isolated hominin upper central permanent incisor dated with Optically Stimulated Luminescence dating of sediments to about 52 - 55 thousand years ago. Specimen SMD-TC-AA210 has a massive crown absolutely and relative to its root size, the crown is wide (mesiodistally) and relatively short (labiolingually). Morphologically, it exhibits a very strong degree of labial convexity, pronounced shovelling, and the bulging basal eminence exhibits several upward finger-like projections. Labial enamel wrinking on the enamel-dentine junction is expressed as two large ridges exhibiting numerous spine-like projections, and the lingual extensions on the enamel surface of the basal eminence are expressed as six extensions. This combination of crown size and morphological traits is not normally found in H. sapiens and instead characterises archaic members of Homo such as H. erectus, H. neanderthalensis and Middle Pleistocene hominins sharing a clade with H. heidelbergensis. The Trader's Cave tooth suggests that an archaic hominin population inhabited northern Borneo just prior to or coincident with the arrival of H. sapiens as documented at the nearby West Mouth of the Niah Great Cave.

H omo erectus is the founding early hominin species of Island Southeast Asia, and reached Java (Indonesia) more than 1.5 million years ago 1 , 2 . Twelve H. erectus calvaria (skull caps) and two tibiae (lower leg bones) were discovered from a bone bed located about 20 m above the Solo River at Ngandong (Central Java) between 1931 and 1933 3 , 4 , and are of the youngest, most-advanced form of H. erectus 5 – 8 . Despite the importance of the Ngandong fossils, the relationship between the fossils, terrace fill and ages have been heavily debated 9 – 14 . Here, to resolve the age of the Ngandong evidence, we use Bayesian modelling of 52 radiometric age estimates to establish—to our knowledge—the first robust chronology at regional, valley and local scales. We used uranium-series dating of speleothems to constrain regional landscape evolution; luminescence, 40 argon/ 39 argon ( 40 Ar/ 39 Ar) and uranium-series dating to constrain the sequence of terrace evolution; and applied uranium-series and uranium series–electron-spin resonance (US–ESR) dating to non-human fossils to directly date our re-excavation of Ngandong 5 , 15 . We show that at least by 500 thousand years ago (ka) the Solo River was diverted into the Kendeng Hills, and that it formed the Solo terrace sequence between 316 and 31 ka and the Ngandong terrace between about 140 and 92 ka. Non-human fossils recovered during the re-excavation of Ngandong date to between 109 and 106 ka (uranium-series minimum) 16 and 134 and 118 ka (US–ESR), with modelled ages of 117 to 108 thousand years (kyr) for the H. erectus bone bed, which accumulated during flood conditions 3 , 17 . These results negate the extreme ages that have been proposed for the site and solidify Ngandong as the last known occurrence of this long-lived species. Bayesian modelling of radiometric age estimates provides a robust chronology for Homo erectus at Ngandong (Java), confirming that this site currently represents the last known occurrence of this species.

Isochron burial dating with cosmogenic nuclides 26 Al and 10 Be shows that the skeleton of the australopithecine individual known as ‘Little Foot’ is around 3.67 million years old, coeval with early Australopithecus from East Africa; a manuport dated to 2.18 million years ago from the Oldowan tool assemblage conforms with the oldest age previously suggested by fauna. An early date for 'Little Foot' australopithecine The cave infillings at Sterkfontein in South Africa contain some of the richest assemblages of fossil hominins in the world. The problem with Sterkfontein and many caves like it is that it is notoriously difficult to date such sediments : they accumulate in a haphazard way with many episodes of deposition, erosion and reworking. Darryl Granger et al . use isochron burial dating with cosmogenic nuclides 26 Al and 10 Be to show that the breccia containing the substantially complete skeleton of the australopithecine individual known as 'Little Foot' is around 3.67 million years old, coeval with Australopithecus afarensis ('Lucy') from East Africa. The earliest stone tools from Sterkfontein are dated to around 2.18 million years ago, a similar age to tools from nearby sites such as Swartkrans. The cave infills at Sterkfontein contain one of the richest assemblages of Australopithecus fossils in the world, including the nearly complete skeleton StW 573 (‘Little Foot’) 1 , 2 , 3 , 4 in its lower section, as well as early stone tools 5 , 6 , 7 in higher sections. However, the chronology of the site remains controversial 8 , 9 , 10 , 11 , 12 , 13 , 14 owing to the complex history of cave infilling. Much of the existing chronology based on uranium–lead dating 10 , 11 and palaeomagnetic stratigraphy 8 , 12 has recently been called into question by the recognition that dated flowstones fill cavities formed within previously cemented breccias and therefore do not form a stratigraphic sequence 4 , 14 . Earlier dating with cosmogenic nuclides 9 suffered a high degree of uncertainty and has been questioned on grounds of sediment reworking 10 , 11 , 13 . Here we use isochron burial dating with cosmogenic aluminium-26 and beryllium-10 to show that the breccia containing StW 573 did not undergo significant reworking, and that it was deposited 3.67 ± 0.16 million years ago, far earlier than the 2.2 million year flowstones found within it 10 , 11 . The skeleton is thus coeval with early Australopithecus afarensis in eastern Africa 15 , 16 . We also date the earliest stone tools at Sterkfontein to 2.18 ± 0.21 million years ago, placing them in the Oldowan at a time similar to that found elsewhere in South Africa at Swartkans 17 and Wonderwerk 18 .

Determining exhumation and cooling rates of regional metamorphic rocks is essential for deciphering orogenic dynamics and heat transport in the Earth's crust. Although radiometric dating is commonly used, its temporal resolution becomes coarser for older rocks, limiting its ability to resolve Precambrian metamorphic timescales. Diffusion chronometry, based on mineral zoning, offers age-independent temporal resolution but is affected by uncertainties in pressure–temperature conditions and diffusion coefficients, which have not been fully evaluated in Paleoproterozoic or older orogens. This study integrated Monte Carlo-based garnet Fe–Mg-Ca-Mn diffusion simulations with phase equilibria modeling to quantify exhumation and cooling rates of pelitic granulites from the Paleoproterozoic Jiao–Liao–Ji orogen, explicitly addressing uncertainty propagation. The granulites record peak pressures of 13–14 kbar at 850–870 °C, followed by heating during decompression to ultra-high-temperature conditions (~ 940 °C, ~ 6.5 kbar) within 2–9 Myr at ca. 1.86 Ga. Subsequent cooling to ~ 5 kbar and ~ 600 °C is nonlinear, with rapid cooling (up to 148 °C/Myr) above 800 °C, and slower cooling (~ 5 °C/Myr) below 700–600 °C. These diffusion-based timescales and rates, with uncertainties of 0.3–0.5 orders of magnitude (1σ), outperform current in situ radioisotope geochronology methods, providing refined constraints on Orosirian geodynamics. The heating during decompression and subsequent nonlinear cooling suggest potential parallels with modern mantle upwellings and extensional tectonics; slower cooling and exhumation rates obtained in this study (when compared to modern systems) potentially reflects a weaker Paleoproterozoic lithosphere. This research highlights the power of diffusion chronometry for understanding of early Earth history.

The cranial morphology of the earliest known hominins in the genus Australopithecus remains unclear. The oldest species in this genus ( Australopithecus anamensis , specimens of which have been dated to 4.2–3.9 million years ago) is known primarily from jaws and teeth, whereas younger species (dated to 3.5–2.0 million years ago) are typically represented by multiple skulls. Here we describe a nearly complete hominin cranium from Woranso-Mille (Ethiopia) that we date to 3.8 million years ago. We assign this cranium to A. anamensis on the basis of the taxonomically and phylogenetically informative morphology of the canine, maxilla and temporal bone. This specimen thus provides the first glimpse of the entire craniofacial morphology of the earliest known members of the genus Australopithecus . We further demonstrate that A. anamensis and Australopithecus afarensis differ more than previously recognized and that these two species overlapped for at least 100,000 years—contradicting the widely accepted hypothesis of anagenesis. Two related studies describe a newly discovered cranium of Australopithecus anamensis , the environment in which this hominin would have lived approximately 3.8 million years ago and how it is related to Australopithecus afarensis .

Pygmy mammoths ( Mammuthus exilis ) and Columbian mammoths ( Mammuthus columbi ) coexisted on the island of Santarosae (now the Northern Channel Islands of California) until the Late Pleistocene megafaunal extinctions, but the ecology of these mammoths is not yet well explored. In this study, we reconstructed the diets and environments of Late Pleistocene pygmy and Columbian mammoths using stable isotopes in tooth enamel samples from the Northern Channel Islands and Rancho La Brea. The enamel δ 13 C values indicate that these mammoths primarily consumed C 3 vegetation. However, a few individuals consumed significant amounts of C 4 plants, CAM plants, or water-stressed woody C 3 plants. The mean diet-δ 13 C value for mainland mammoths (−24.2 ± 1.4‰) is about 2‰ higher than that of island mammoths (−26.4 ± 1.9‰), suggesting that most mainland mammoths consumed either water-stressed C 3 vegetation, or some C 4 and/or CAM plants. Reconstructed δ 18 O values of paleo-water from the mainland are generally lower than the mean δ 18 O values of modern precipitation in Southern California, suggesting conditions were wetter and/or cooler than today. Reconstructed δ 18 O values of paleo-water from the islands are more similar to modern precipitation. δ 13 C-based estimates of mean annual precipitation range from 159 to 1407 mm/yr on the islands and from 28 to 387 mm/yr on the mainland. However, consumption of small amounts of C 4 and/or CAM plants may have resulted in an underestimation of precipitation for the mainland. Radiometric dating of additional fossils from both localities will help clarify the links between climate change and mammoth evolution and extinction in the region.