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Mwanganda's Village (MGD) and Bruce (BRU) are two open-air site complexes in northern Malawi with deposits dating to between 15 and 58 thousand years ago (ka) and containing Middle Stone Age (MSA) lithic assemblages. The sites have been known since 1966 and 1965, respectively, but lacked chronometric and site formation data necessary for their interpretation. The area hosts a rich stone artifact record, eroding from and found within alluvial fan deposits exhibiting poor preservation of organic materials. Although this generally limits opportunities for site-based environmental reconstructions, MGD and BRU are located at the distal margins of the alluvial fan, where lacustrine lagoonal deposits were overprinted by a calcrete paleosol. This has created locally improved organic preservation and allowed us to obtain ecological data from pollen, phytoliths, and pedogenic carbonates, producing a regional-to site-scale environmental context for periods of site use and abandonment. Here, we integrate the ecological data into a detailed site formation history, based on field observations and micromorphology, supplemented by cathodoluminescence microscopy and mu-XRF. By comparing local, on-site environmental proxies with more regional indicators, we can better evaluate how MSA hunter-gatherers made decisions about the use of resources across the landscape. Our data indicate that while tree cover similar to modern miombo woodland and evergreen gallery forest prevailed at most times, MSA hunter-gatherers chose more locally open environments for activities that resulted in a lithic artifact record at multiple locations between 51 and 15 ka.(C) 2022 The Authors. Published by Elsevier Ltd. info:eu-repo/semantics/publishedVersion

The African Middle Stone Age (MSA, typical range ~ 320–30 ka) has been the subject of intense research interest in recent decades as a culture-chronological Unit associated with the emergence and dispersal of our species. Recent results of this work have shown that sites designated as “MSA” contain common approaches to lithic reduction, but that within this rubric, there is much diversity in overall assemblage characteristics and the timing of their appearance across the continent. As researchers recover more data from more sites, especially from undersampled geographic regions, this more complex picture of the MSA reveals technological and other behavioral diversity in early modern human populations that may inform about the ultimate success of our species. Here we add to this growing database by describing the environmental context and characteristics of two concentrations of stone artifacts from the late MSA (~ 43–21 ka) open-air locality of Chaminade-I (CHA-I), near the town of Karonga in northern Malawi. The CHA-I lithic artifacts show a flexible approach to stone tool production and use that is common to assemblages in Karonga but distinctive from MSA sites reported elsewhere. Radial and minimally reduced cores typify an unelaborated lithic assemblage, in which raw material choice is driven by toolstone clast size and shape rather than preferential use or treatment of specific materials, as found in MSA assemblages in the East African Rift, South Africa, and the North African coast. Lithic reduction at CHA-I took place within a woody, riparian context embedded within a more open woodland landscape. Most artifacts occurred in near-channel sandy deposits dated to ~ 41 ka, and were buried under alluvial fan deposits that began aggrading by at least ~ 21 ka and continued beyond ~ 5.5 ka within a grassy, open landscape. The site’s late MSA age and lack of elaboration in lithic technology challenges straightforward ideas of increasing complexity in human technological behavior over time and provides important insight into the diversity of MSA technologies and the environmental conditions in which they existed.

Modern Homo sapiens engage in substantial ecosystem modification, but it is difficult to detect the origins or early consequences of these behaviors. Archaeological, geochronological, geomorphological, and paleoenvironmental data from northern Malawi document a changing relationship between forager presence, ecosystem organization, and alluvial fan formation in the Late Pleistocene. Dense concentrations of Middle Stone Age artifacts and alluvial fan systems formed after ca. 92 thousand years ago, within a paleoecological context with no analog in the preceding half-million-year record. Archaeological data and principal coordinates analysis indicate that early anthropogenic fire relaxed seasonal constraints on ignitions, influencing vegetation composition and erosion. This operated in tandem with climate-driven changes in precipitation to culminate in an ecological transition to an early, pre-agricultural anthropogenic landscape. Introduction Results - Geochronology and geomorphology - Archaeology - Paleoclimate and environment reconstruction - Paleoenvironmental analysis Discussion Material and methods - Fieldwork survey, excavation, and profile documentation - OSL dating - Lithic analysis - Micromorphology and carbonate dating - Phytolith analysis - Statistical methods

The Southern Montane Forest-Grassland mosaic ecosystem in the humid subtropics southern Rift Valley of Africa comprised the environmental context for a large area in which modern human evolution and dispersal occurred. Variable climatic conditions during the Late Pleistocene have ranged between humid and hyperarid, changing the character of the ecosystem and transforming it at different points in time into a barrier, a refuge, and a corridor between southern and eastern African populations. Alluvial fans presently blanket the areas adjacent to major river systems, which were key areas of prehistoric human habitation. These sets of variables have created conditions that are both challenging and advantageous to conduct archaeological research. Lateritic soil development has resulted in poor organic preservation and facilitated insect bioturbation, which has demanded an integrated micro-macro scale approach to building a reliable geochronology. An integrated field and analytical methodology has also been employed to identify the nature and degree of post-depositional movement in alluvial deposits, which preserve a wide range of spatial integrity levels in buried stone artifact assemblages between 47 and 30 ka in Karonga, northern Malawi. This paper describes the methodological advances taken toward understanding open-air Middle Stone Age archaeology in sub-tropical Africa, and explores the inferential potential for understanding Pleistocene human ecology in the important southern Rift Valley region.

A braincase of the Cretaceous titanosaurian sauropod Malawisaurus dixeyi, complete except for the olfactory region, was CT scanned and a 3D rendering of the endocast and inner ear was generated. Cranial nerves appear in the same configuration as in other sauropods, including derived features that appear to characterize titanosaurians, specifically, an abducens nerve canal that passes lateral to the pituitary fossa rather than entering it. Furthermore, the hypoglossal nerve exits the skull via a single foramen, consistent with most titanosaurians, while other saurischians, including the basal titanosauriform, Giraffatitan, contain multiple rootlets. The size of the vestibular labyrinth is smaller than in Giraffatitan, but larger than in most derived titanosaurians. Similar to the condition found in Giraffatitan, the anterior semicircular canal is larger than the posterior semicircular canal. This contrasts with more derived titanosaurians that contain similarly sized anterior and posterior semicircular canals, congruent with the interpretation of Malawisaurus as a basal titanosaurian. Measurements of the humerus of Malawisaurus provide a body mass estimate of 4.7 metric tons. Comparison of body mass to radius of the semicircular canals of the vestibular labyrinth reveals that Malawisaurus fits the allometric relationship found in previous studies of extant mammals and Giraffatitan brancai. As in Giraffatitan, the anterior semicircular canal is significantly larger than is predicted by the allometric relationship suggesting greater sensitivity and slower movement of the head in the sagittal plane.

We assembled genome-wide data from 16 prehistoric Africans. We show that the anciently divergent lineage that comprises the primary ancestry of the southern African San had a wider distribution in the past, contributing approximately two-thirds of the ancestry of Malawi hunter-gatherers ∼8,100-2,500 years ago and approximately one-third of the ancestry of Tanzanian hunter-gatherers ∼1,400 years ago. We document how the spread of farmers from western Africa involved complete replacement of local hunter-gatherers in some regions, and we track the spread of herders by showing that the population of a ∼3,100-year-old pastoralist from Tanzania contributed ancestry to people from northeastern to southern Africa, including a ∼1,200-year-old southern African pastoralist. The deepest diversifications of African lineages were complex, involving either repeated gene flow among geographically disparate groups or a lineage more deeply diverging than that of the San contributing more to some western African populations than to others. We finally leverage ancient genomes to document episodes of natural selection in southern African populations. PAPERCLIP.

The Chiweta Beds of Malawi have yielded a diverse late Permian fossil tetrapod fauna that correlates with that of the Cistecephalus Assemblage Zone of the South African Karoo Supergroup. Amongst the fossil therapsids from the Chiweta Beds is the well-preserved skull and lower jaw of a burnetiamorph, a group of biarmosuchians with numerous bosses and swellings on the skull. This specimen was reported in a preliminary paper in 2005 as the first burnetiamorph described outside of South Africa and Russia. Reanalysis of the morphology and phylogeny of this specimen places Lende chiweta, gen. et sp. nov., as the sister taxon to the clade formed by Proburnetia (Paraburnetia (Pachydectes, Bullacephalus, Burnetia, Niuksenitia)). The greatest diversity of this basal therapsid group is from South Africa, with six of nine described genera and a stratigraphic range that extends from the middle Permian Tapinocephalus Assemblage Zone to the upper Permian Dicynodon Assemblage Zone. Bearing in mind the constraints...