We report a new Middle Pleistocene paleoanthropological locality located in southern Iberian Peninsula, Ruidera, and describe a newly discovered partial parietal bone (RVH-1). The fossil was chronologically constrained through a combination of uranium-series and optically stimulated luminescence dating methods. In particular, the human fossil-bearing breccia may be tentatively dated to between 224 ± 14 ka and 160 ± 10 ka, although an older age cannot be entirely excluded, given the inherent uncertainty in the gamma dose rate evaluation. When considering these new results together with those previously obtained on Caprinae fossil teeth from that same layer, we can reasonably propose a late (second half) Middle Pleistocene age for the Ruidera fossil locality. Morphological analysis shows that RVH-1 exhibits relatively high cranial vault thickness and parietal angle compared with Iberian Middle Pleistocene samples such as the preneanderthals from Sima de los Huesos from Atapuerca (Spain). However, both variables fall within the broader range of variation observed across Homo heidelbergensis (both s.l. and s.s.). In this context, RVH-1 appears to be closer to specimens often described as more plesiomorphic in Europe (e.g., Ceprano) and to some African Middle Pleistocene individuals (e.g., Kabwe). These results highlight the considerable variability in cranial morphology during the Middle Pleistocene and caution against strong taxonomic or phylogenetic interpretations based on isolated traits. RVH-1 is therefore best interpreted within a framework of morphological variability in Europe. RVH-1 provides a critical addition to the European human fossil record, which remains very fragmented for the Middle Pleistocene.

The evolutionary transformation of the hominin hand is of central interest due to its critical role in mediating interaction with both the physical and cultural environments. Beyond its functional significance, however, hand morphology can also reflect broader anatomical trends at the organism level. This study analyzes 31 metacarpal remains from the Neandertal site of El Sidrón (Asturias, Spain), using a combination of discrete morphological traits, linear measurements, and three-dimensional geometric morphometrics based on a 32-landmark template. The dataset is examined within a broad comparative and evolutionary framework. Our results confirm that Neandertal metacarpals differ markedly from those of modern Homo sapiens. They display increased robustness, more strongly developed muscle attachment sites, and enlarged heads, resulting in the characteristic 'lollipop' morphology. Significant differences are also observed in the carpometacarpal joint complex, including a flattened proximal articular facet on the first metacarpal, a reduced styloid process on the third metacarpal, and the absence of torsion in the fifth metacarpal, which also affects its articulation with the fourth metacarpal. Although these traits have often been interpreted as localized functional adaptations related to grip strength, joint loading, and manipulative performance, our results support a complementary anatomical interpretation. Comparable patterns of skeletal hypertrophy and joint reorganization (e.g., articular surface flattening and surface rotation) have been described in other Neandertal anatomical regions (including the clavicle, elbow, sacrolumbar spine, wrist, and femur), suggesting that metacarpal morphology may form part of a broader systemic pattern of skeletal organization. We therefore interpret the Neandertal metacarpals as compatible with an organism-level perspective, while emphasizing that behavioral and functional inferences require additional lines of evidence.

Species boundaries are central to evolutionary biology, yet the reliability of skeletal morphology, particularly isolated postcranial elements, for diagnosing species remains unresolved. Long bones are commonly recovered in the fossil record and often used as operational taxonomic units but are shaped by functional and developmental constraints that may decouple morphological differentiation from species diagnosability. Here, morphological variation in the humerus and femur is examined across extant great apes to assess their utility for species delimitation, with implications for extinct hominins. At the genus level, differences between groups are expressed through significant differences in morphology and commonly in disparity. Among species-level taxa, mean shape differences were consistently detected, although without corresponding differences in disparity, indicating morphological differentiation within a constrained envelope. The results further indicate that the femur may be more informative than the humerus for detecting taxonomic and functional signals among hominids and that data availability can influence results obscuring morphological differences, as demonstrated by simulations on fragmentary bones and analyses of landmark taxonomic signals. Overall, these findings show that although postcranial long bones can track morphological changes and retain valuable taxonomic signals, they remain weak proxies for species boundaries when studied in isolation, with direct implications for taxonomic identification in the hominin fossil record.

Hominin lumbar vertebrae are characterized by adaptations for bipedal locomotion, which are mostly known from adults. However, vertebrae of Homo erectus are exclusively known from immature individuals. As such, understanding the ontogeny of lumbar vertebrae is warranted. Here, we use three-dimensional geometric morphometrics to quantify the morphology of three H. erectus upper lumbar vertebrae, D2672 from Dmanisi, Georgia; KNM-WT 15000 from Nariokotome, Kenya; and SK 853 from Swartkrans, South Africa, as well as those of two Australopithecus sediba U.W.88-92 and U.W.88-232 from Malapa, South Africa, in a comparative developmental context to assess the likely vertebral positions of D2672 and SK 853. The result suggests that the vertebral position of D2672 cannot be distinguished between the first and second lumbar vertebrae, while SK 853 most likely represents a first lumbar vertebra. We also quantified the ontogenetic variation in the first and second lumbar vertebrae of modern humans, from late infancy to full adulthood, and compared these with H. erectus. In modern humans, the lumbar vertebrae increase in size and undergo a series of shape changes across ontogeny. In particular, the vertebral canal relatively decreases in dorsoventral length but increases in mediolateral length with age, thus juveniles possess relatively narrower vertebral canals than adults. All H. erectus individuals fall within the range of modern humans at a comparable developmental stage in the morphospace, despite their smaller size, suggesting that the vertebral traits associated with humanlike bipedal locomotion were established relatively early in ontogeny and in the evolutionary process.

A richly fossiliferous sandstone outcrop in the Wasatch Formation, Great Divide Basin, southern Wyoming, has yielded exceptionally well-preserved fossils of three omomyid primates. Here we report new occurrences of two rarely documented omomyids, Arapahovius gazini and Anemorhysis savagei, describe a new species of Tetonius, and perform a phylogenetic analysis of Tetonius and its allies; the two previously described omomyids are new additions to the fossil record of the Great Divide Basin and represent only the second and third occurrences of these species, respectively. Tetonius, Arapahovius, and Anemorhysis are not known to co-occur elsewhere, particularly in the well-documented Bighorn Basin of northwestern Wyoming, where the Tetonius + Pseudotetonius clade is locally extirpated prior to the first appearances of Arapahovius and Anemorhysis. Morphological support for the new species of Tetonius is corroborated by biostratigraphic data suggesting it is younger than Pseudotetonius ambiguus from the Bighorn Basin. However, the new species of Tetonius retains key dental symplesiomorphies that signal a relatively early divergence from the Tetonius + Pseudotetonius clade as it is recorded in the Bighorn Basin. Results from our maximum parsimony analysis indicate that Tetonius varleyorum sp. nov. from the Great Divide Basin is more closely related to P. ambiguus than either of the species of Tetonius known from the Bighorn Basin, underscoring the paraphyletic status of Tetonius with respect to Pseudotetonius proposed by earlier workers. The evolutionary history of the Tetonius + Pseudotetonius clade was more complex than previously recognized, and this added complexity can only be recognized through broader geographic sampling.

A comprehensive and accurate database of the human fossil record is a necessity for synthetic understanding of hominin biological and behavioral evolution, yet it has remained an elusive goal for decades. This paper presents a conceptual framework for an online database of the human fossil record, called Origins, and an implementation of that framework for the 1200+ hominin fossils of the Omo-Turkana Basin of northern Kenya and southern Ethiopia. The Omo-Turkana Basin is one of the largest and most significant hominin fossil assemblages in Africa and marks the first major milestone in developing a comprehensive database for the entire hominin fossil record globally. We discuss the theoretical foundation underlying the conceptual model used for Origins, the technical details for the establishment and utilization of Origins, and the roadmap for future and ongoing development of this resource.

This study presents an incised ochre artefact from the Yanling site in the Luonan Basin, the Qinling Mountains region, central China. The specimen, recovered from a well-stratified paleosol, bears deep incisions consistent with intentional scoring. The optical stimulated luminescence dating results indicate that the artefact dates to approximately 80 ka ago. Physicochemical analyses, including X-ray fluorescence, X-ray diffraction, and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, reveal that the sample consists primarily of iron oxides and clay minerals, which are some of the most frequent constituents in ochre materials and thus support the artefact's identification as an ochre piece. This finding represents the earliest known incised ochre artefact from East Asia and provides new evidence for ochre use and behavioral complexity in the region.

The upper middle Eocene Pondaung Formation of central Myanmar has yielded some of the earliest stem anthropoids outside Afro-Arabia. In contrast, strepsirrhine primates are rare and previously known only from the small-bodied sivaladapids Kyitchaungia takaii and Paukkaungia parva. Here we report a new large-bodied sivaladapid based on an isolated M[3] from Pondaung, described as Guangxilemur rarissimus sp. nov. The tooth exhibits diagnostic features of Guangxilemur, including a subrectangular outline, a deep trigon basin, an incipient mesostyle, a well-developed buccal cingulum, and pronounced enamel wrinkling. Its dimensions indicate a body mass of approximately 4.1-4.8 kg, substantially larger than previously known Pondaung strepsirrhines and closely matching estimates for the controversial partial postcranial skeleton NMMP 20, previously attributed to the amphipithecine Pondaungia. Because NMMP 20 displays clear strepsirrhine affinities and corresponds in size to G. rarissimus, we reassign this specimen to the new taxon. This resolves the long-standing debate over the phylogenetic identity of NMMP 20 and eliminates a major source of conflict between craniodental and postcranial data, hampering previous interpretations of early anthropoid evolution in Asia. Additional material of Paukkaungia supports the recognition of greater ecological diversity among sivaladapids within the Pondaung primate community.

A growing body of archaeological data points towards distinct cultural innovations during Marine Isotopic Stage (MIS) 5 in Africa. At Bushman Rock Shelter in South Africa, we described previously a large corpus of end-scrapers that constitute a technological novelty in the context of MIS 5 developments. Here, we describe 25 bones with impressions collected from the same deposits. Middle Stone Age layers at the site represent a succession of distinct technological phases, but the bones with impressions are strictly associated with one of them only, characterised by the presence of end-scrapers. Our refined optically stimulated luminescence and U-series chronology, presented here, dates securely this technological association to 103 ± 3 ka. Amongst the bones with impressions, there is a marked preference for the diaphyses of large ungulate long bones. Scraping marks linked to periosteum removal and evidence of fresh breakage indicate the use of bones while still fresh. Macro- and microscopic characteristics of the used areas confirm that the bones were used during percussive activities. The orientation of the bone surface modifications indicates repeated, similar technological gestures. We propose that these bones with impressions are bone retouchers that were fully integrated into the production of the end-scrapers and that they document a clear technological imbrication between the processing of animal resources and the manufacture and use of stone tools. We argue that the use of bones in lithic retouching or resharpening activities represents a critical step in the technological process that led to the exploitation of bone as a versatile raw material by hunter-gatherers.

The functional role of the gluteus medius differs between extant humans and other primates. In nonhuman primates, the muscle rotates the pelvis in the horizontal plane and assists forelimb reach. By contrast, in humans, it pulls the pelvis upward in the frontal plane and contributes to mediolateral stability during bipedal gait. In the earliest evolutionary stage of bipedalism, however, a functional flexibility would have been required to cope with both bipedalism and locomotion using all four limbs. This study conducted a moment arm analysis based on a model-kinematics matching approach in Japanese macaques (Macaca fuscata), which lack any morphological adaptations for bipedalism. We hypothesized that it was postural change itself that triggered the functional transition of the gluteus medius. The primary action of the gluteus medius was found to shift from medial rotation to abduction with a change from quadrupedal to bipedal walking. This is likely to have been caused by a change in the geometric relationship between the muscular force vector and femoral orientation. This indicates that the gluteus medius has the faculties to change its action regardless of iliac morphology while also suggesting that the behavioral changes preceded morphological adaptations in the evolutionary process of the hip abductor apparatus. In the earliest evolutionary stage, a versatile gluteus medius likely facilitated mediolaterally stable bipedal gaits while ensuring the kinematic demands of quadrupedal locomotion, which led to a seamless locomotor transition to bipedalism.

We used traits from the Arizona State University Dental Anthropology System (ASUDAS) to investigate the Out-of-Africa II dispersal (∼70,000-50,000 BP) and biogeographic dynamics within the continent since the Late Pleistocene. Mean measure of divergence (MMD) distances from 32 recent global and five Early-Late Holocene African dental samples (n = 3167 individuals) were compared with FST distances from matched genetic samples (n = 566), serving as an independent line of validation. We then incorporated multidimensional scaling (MDS), Mantel correlations, linear regression, and novel minimum-slope geographic distances to reconstruct global population structure. Strong correlations (rm > 0.7) resulted between MMD and FST matrices and between the latter and their respective minimum-slope distances. The dental and genetic MDS plots revealed the patterning characteristic of seriated spatial or temporal data, indicating greater diversity within Africa than outside of it. Inclusion of the ancient samples revealed long-term phenetic continuity in East and South Africa and a south-north gradient in dental variation. Regressing MDS coordinates against minimum-slope distances yielded the highest R[2] value for recent and ancient South African samples (≤0.86), mirroring genetic clines linked with deep Pleistocene structure and Holocene population movements. These findings are consistent with isolation by distance and compatible with serial founder processes associated with the Late Pleistocene dispersal from East Africa. They also suggest Sub-Saharan Africans had formed regionally structured but interconnected populations throughout the Holocene, with South African groups retaining high diversity and features reflecting deep ancestry. Overall, the ASUDAS traits broadly track population history and patterns observed in neutral genomic structure.

Transformative technologies that alter raw material properties, rather than just raw material shape and size, are key proxies for the evolution of human cognition and social learning. Silcrete heat treatment in the southern African Middle Stone Age (MSA) is one such proxy. Yet debate now centers not on whether heat treatment occurred in the African MSA but on how it was organized across settings-from controlled insulated setups to embedded hearth-side practices-and how factors such as raw material properties and fire management conditioned those choices. In this study, we argue that archaeological heating-temperature distributions for silcretes provide a proxy for reconstructing fire-use contexts, which in turn allow inference of how heat treatment was organized within broader domestic and social practices. We apply a nondestructive near-infrared protocol-targeting changes in silanol (SiOH) and molecular water (H2O)-to estimate heating temperatures for Howiesons Poort artefacts from Diepkloof and Mertenhof Rock Shelters. As calibration, we use a dataset comprising 225 observations on silcrete flakes heated to prespecified temperatures, which underpins both categorical classification and continuous temperature prediction for the archaeological collection. Heating temperature estimates for the archaeological materials cluster at ∼400-450 °C-an established optimal range for improving silcrete knappability-with smaller numbers of lower and higher values forming expected tails, a pattern that implies intentional fire temperature management by humans. This distribution of temperature estimates is more consistent with lateralized heating adjacent to domestic hearths than with tightly controlled insulated systems. While such a pattern does not uniquely demonstrate embedded heat treatment, it is most parsimoniously explained by routine placement of silcrete within the thermal gradients of domestic fires rather than by the use of segregated, specialized heating systems. We suggest that later MSA groups possessed the capacity for tightly controlled heating but typically met technological goals with minimal organizational overhead, reflecting risk-sensitive choices about time, fuel, and raw material fracture. By showing how a transformative technology was integrated into routine domestic contexts, our results highlight cross-domain cognition and probably low-friction social transmission as key dimensions of later MSA technologies-traits that foreshadow later expansions of complexity in Homo sapiens.

The development of hypotheses regarding the specific ways in which environmental change influenced hominin evolution is often hampered by time-averaged paleoenvironmental reconstructions. The rich and continuous fossil record of the Shungura Formation provides an excellent opportunity to reconstruct paleoenvironments in narrower temporal intervals to better elucidate the degree of variability in hominin habitats. Here, we reconstruct submember-scale habitat variation in Member G (2.26-1.92 Ma) by applying a novel three-dimensional (3D) geometric morphometric approach to bovid astragalus ecomorphology. Using canonical variates analyses and between-group principal components analysis with extant bovids (n = 136), we investigate how 3D astragalus shape can distinguish among four habitat categories with varying vegetation cover (forest, heavy cover, light cover, and open). When those models are applied to complete fossil astragali from Member G (n = 195), we find that astragali representing all four categories are present throughout, but varying proportions of each category suggest shifts in the relative abundance of wooded vs. open habitats. The base of Member G is inferred as more open, with a shift toward more wooded habitats from submember G-7 to G-12, followed by a return to more open habitats. This trend cannot be solely attributed to variable preservation among submembers as it occurs within a consistent depositional setting. This underscores that Member G is characterized by short-term fluctuations in paleoenvironmental conditions and demonstrates the utility of this 3D approach for reconstructing subtle environmental shifts.