The theoretical starting point is deceptively simple. Classical groundwater flow theory, dating back to József Tóth’s work in 1963, holds that recharge falling on elevated terrain moves through the subsurface along shallow, intermediate, and deep flow paths toward valleys and discharge zones. Topography, recharge, and hydraulic conductivity jointly control how these paths organize. But the relationship runs both ways: groundwater does not merely respond to topography—it actively carves it. Through seepage-driven erosion and sapping, emerging groundwater undercuts slopes, triggers collapse, and drives headward retreat of valley heads, leaving amphitheatre-shaped valleys etched into escarpments. Coupled hydrologic–geomorphic models have shown that landscapes co-evolve with their subsurface flow systems, meaning that terrain form should, in principle, carry the imprint of the architecture of the aquifer beneath.

To exploit this idea, the team selected two mountain systems broadly comparable in first-order climatic and topographic setting while differing in subsurface structure. The East African analogue centers on the Jema basin in the central to south-central Ethiopian Highlands, a Cenozoic volcanic terrain uplifted by mantle plume activity and deeply dissected. The South African counterpart is the Drakensberg escarpment-to-Indian Ocean transect encompassing the uThukela–uMngeni (UU) region, an older Karoo terrain of stacked flood basalts overlying layered sedimentary rocks. Both regions share basement rocks at depth, sedimentary units in the middle, and volcanic plateaus above, and both were shaped by plume-related volcanism and multi-stage denudation. Crucially, the comparison was restricted to subregions with similar aridity index, rainfall regime, and relief, so that differences in geomorphic expression could be interpreted more directly in terms of subsurface controls rather than climate-driven recharge contrasts.

The analysis relied on 30-meter digital elevation models processed with identical Python-based terrain analysis for both regions. Three complementary geomorphic indicators were quantified: the distribution of amphitheatre-headed valleys, slope–area scaling relationships, and channel sinuosity within wetland systems. Potential sapping-related landforms were extracted by selecting high-slope areas above the 90th percentile combined with strong concave–convex curvature above the 80th percentile, with spatial continuity evaluated within a 9-by-9-cell neighborhood. Drainage networks were extracted using a common contributing-area threshold of one square kilometer, and channel sinuosity was computed as the ratio of channel length to straight-line end-to-end distance for segments longer than 200 meters. The consistency of method was essential: any difference in the resulting geomorphic organization could then be attributed to the terrain itself rather than to analytical choices.

The results reveal systematic divergence. In the Jema sector of the Ethiopian Highlands, the extracted sapping features form laterally aligned, deeply indented valley heads along the northern plateau margin—a discontinuous but coherent zone of headward retreat associated with steep escarpment slopes, sparse tributaries, and pronounced amphitheatre-like embayments. The slope–area analysis shows that for equivalent contributing area, Jema channels consistently exhibit higher slopes than UU channels, expressed as an upward displacement of the slope–area cloud, most pronounced in the intermediate drainage-area range of roughly 10^6 to 10^8 square meters. This elevated upper envelope is consistent with theoretical expectations for landscapes influenced by subsurface flow, where groundwater emergence promotes localized incision and sustains steeper gradients. In contrast, the UU region displays a dense, highly integrated drainage network with closely spaced channels and uniform headwater development, tightly constrained slope–area distributions, and limited organized sapping expression—signatures of runoff-driven fluvial incision dominating landscape evolution.

The wetland story adds a further twist. In the South African UU region, wetlands are laterally extensive, occupying broad, low-gradient valley floors with shallow, weakly incised, and highly sinuous channels. Floodplain depressions, abandoned meanders, oxbow-like forms, and relict channels indicate active floodplain storage and strong surface–groundwater interaction. In the Jema region, wetlands are more limited and discontinuous, occurring mainly as small depressions or localized wet valley-floor pockets, with more confined channels showing fewer abandoned meanders. Taken together, the UU system expresses a shallow, laterally connected groundwater–surface water regime, while Jema shows more discrete wetland expression and spatially focused groundwater discharge consistent with deeper circulation. Remarkably, this divergence inverts expectations based on relief alone: the higher-relief UU terrain exhibits the shallower flow organization, demonstrating that relief does not control slope–area behaviour or drainage form in the absence of process controls associated with groundwater influence.

The geomorphic interpretation was then checked against independent published hydrogeological evidence, including environmental isotopes such as δ18O, δ2H, tritium, and radiocarbon, groundwater residence times, salinity distributions, hydrochemical facies evolution, regional piezometry, and structural mapping of dolerite intrusion networks. The convergence is striking. In the Ethiopian volcanic aquifers, groundwater is generally young—commonly on the order of hundreds to a few thousand years—and remains relatively fresh, implying faster circulation, greater lateral connectivity, and more effective flushing. Multiple studies indicate that groundwater in Ethiopia’s volcanic and tectonically integrated terrains moves beyond local catchment boundaries through laterally continuous volcanic aquifers, with documented inter-basin transfer between the Blue Nile and Awash basins and regional flow paths extending several tens of kilometres. Deep rift-floor waters are largely tritium-free and regionally connected along faulted volcanic blocks, and long-distance circulation helps sustain distant springs and wetlands, locally buffering hydrologically closed basins as hydro-refugia that have played a role in human evolution and dispersal.

The Karoo picture is the mirror opposite. Groundwater in the South African terrain is commonly concentrated within shallow weathered and fractured zones, with flow that is matrix-fed and fracture-controlled, and with low-discharge springs emerging where sparse, weakly connected structures intersect the surface. Recent work from the Eastern Karoo explicitly characterizes groundwater flow as discontinuous and structurally compartmentalized, with flow lines mirroring local topography—signs of limited regional connectivity. Deeper and sub-thermal groundwaters are old, with low radiocarbon, little or no tritium, and residence times that may extend to tens of thousands of years, up to 20,000 years in some cases, suggesting sluggish renewal and slow vertical exchange. High-salinity groundwater at depth further supports long residence times and limited flushing. The authors hypothesize that dense dolerite intrusions in the Karoo—locally reaching up to 30 percent by volume and forming an interconnected, anastomosed stockwork-like system—suppress lateral connectivity, acting primarily as cross-cutting barriers that deflect and compartmentalize groundwater flow rather than sustain vertically integrated regional circulation. In Ethiopia, by contrast, dyke emplacement occurs mainly as discrete plume-related swarms with cumulative dilation around one percent, while layered, interbedded volcanic sequences with scoriaceous flow tops, vesicular horizons, volcanic ash, ignimbrites, and intertrappean sediments sustain permeability with depth through laterally extensive interflow zones.

The management implications are as contrasting as the flow systems themselves. In the Ethiopian Highlands, structurally connected volcanic aquifers appear to support laterally integrated circulation, allowing recharge to move beyond local surface-water divides and re-emerge far from recharge areas. Local abstraction may therefore depend partly on recharge originating tens of kilometres away, implying that groundwater sustainability cannot be evaluated solely from local water balances and that basin-wide assessment, monitoring, and conceptualization incorporating structural controls and inter-basin transfer are required. In the South African Karoo, aquifer compartmentalization suggests that groundwater systems are more strongly controlled by local recharge, shallow storage, and catchment-scale groundwater–surface water interaction, making local to sub-catchment water balances, recharge estimation, wetland protection, and monitoring of streamflow response to abstraction the more effective management approach. The contrasting architectures also imply different modelling requirements: regional-scale conceptualization for Ethiopian volcanic systems versus local to intermediate-scale models focused on groundwater–surface water coupling for compartmentalized Karoo systems.

The novelty of the study lies not in treating any individual geomorphic feature as diagnostic of groundwater—many such features are already well recognized and non-unique when considered alone—but in evaluating whether the combined spatial organization of complementary geomorphic metrics can distinguish contrasting styles and scales of groundwater-flow organization. The approach is explicitly proposed as an exploratory, hypothesis-generating framework for screening groundwater-flow organization in data-scarce mountain environments rather than as a uniquely diagnostic method. The authors acknowledge limitations: the 30-meter DEM cannot resolve small seepage faces or fine-scale valley-head morphology, the interpretation is qualitative and does not directly quantify fluxes or hydraulic properties, and geomorphic signatures may reflect both long-term landscape evolution and present-day hydrological forcing. Future work should test the interpretations using dated geomorphic markers, palaeoclimate data, field hydrogeology, tracers, geophysics, and numerical modelling. Nevertheless, the results reinforce the value of viewing groundwater both as a driver of landscape evolution and as a system whose organization can be partly inferred from landscape form where direct data remain sparse—a perspective that could prove transformative for water security across Africa’s densely populated mountain regions.

Subject of Research: Earth Science

Article Title: Contrasting groundwater flow systems in comparable African Mountains-role of permeability structure

Article References: Kebede, S., Roopa, S., Mongala, T., & Ayalew, D. (2026). Contrasting groundwater flow systems in comparable African Mountains-role of permeability structure. Frontiers in Water, 8, Article 1925623. https://doi.org/10.3389/frwa.2026.1925623

Image Credits: AI Generated

DOI: 10.3389/frwa.2026.1925623

Keywords: groundwater, hydrogeology, geomorphology, Ethiopian Highlands, Drakensberg, Karoo, permeability, mountain hydrology, water resources, Africa, Contrasting, flow

The fossil belongs to Choerosaurus dejageri, an enigmatic therocephalian therapsid that lived roughly 259 million years ago during the late Permian period. Therocephalians are close relatives of cynodonts, the group that gave rise to mammals, and baurioid therocephalians in particular evolved strikingly mammal-like features. Yet while their Triassic descendants have been studied extensively, the Permian members of the clade remain poorly known, and Choerosaurus has not received a detailed anatomical description since it was first briefly characterized in 1929.

A team led by Alessandro Gigliotti of Humboldt-Universität zu Berlin and the Museum für Naturkunde Berlin, working with colleagues from Princeton University, the North Carolina Museum of Natural Sciences, and the University of the Witwatersrand, has now changed that. The researchers CT-scanned the holotype specimen, SAM-PK-8797, housed at the Iziko South African Museum in Cape Town, using a Phoenix VTomeX L240 system with an isotropic voxel size of just 0.050 millimeters. That resolution allowed them to digitally segment and reconstruct bones that had previously been obscured by matrix or crushed beyond recognition, including the previously obscure palatal region at the roof of the mouth.

Choerosaurus is a strange animal even by therocephalian standards. Uniquely among its kind, it sports exaggerated hemispheric bosses on its cranium and lower jaw, structures that earlier CT-assisted work suggested were used in display behavior or low-energy combat, possibly covered by a cornified sheath and deployed in intimidation or ritualized sexual behavior. The new reconstruction confirms these bosses consist of two distinct types of spongy bone, a cancellous hollowed core and a denser outer layer traversed by radially oriented canals, and that their surfaces are perforated by numerous foramina likely associated with branches of the infraorbital nerve, supporting a tactile role in display.

But the real headline concerns the palate. The secondary palate, the bony shelf that separates the nasal passage from the oral cavity, is a hallmark of mammals, allowing simultaneous mastication and respiration. Within synapsids, the broader group that includes mammals and their extinct relatives, a closed secondary palate evolved independently multiple times: once in anomodonts, several times in therocephalians, and again early in cynodont history. The new study shows that Choerosaurus captures a crucial transitional stage in the therocephalian version of this story.

In Choerosaurus, the vomer, a midline bone of the snout, plays the role of an important bracing element in the palate. It forms a long sutural connection with the medially projecting shelves of the maxilla, a structure the researchers call the maxillo-vomerine bridge, which extends from the level of the upper canine to around the level of the third upper postcanine. This differs markedly from the early cynodont condition, where the palate is built instead from the medial projections of the maxillae and palatines, with the vomer excluded from the external palatal surface. The contrast highlights that therocephalian and cynodont secondary palates have different evolutionary origins despite their similar function.

The team also found that the palatal morphology of Choerosaurus closely resembles that of Lycideops longiceps, another lycideopid baurioid, supporting the hypothesis of a close relationship between the two taxa. Lycideopidae currently includes just four species, and the family is of particular importance because it exemplifies the evolutionary trajectory of non-cynodont therapsids across the Permo-Triassic boundary, showing a trend toward smaller body sizes and more delicate skulls, an instance of the so-called Lilliput Effect following the end-Permian mass extinction.

The functional significance of the palate may explain why it kept evolving independently. The researchers argue that similar selective pressures likely underpinned its origin in different lineages: strengthening the snout, providing an enhanced surface for food processing, and maintaining respiratory function during food intake. In predatory forms, trends toward palatal closure may have been tied to increasing bite force or prey handling techniques like lateral head shaking. In herbivorous forms, such as the bauriid therocephalians that were the only successful Triassic radiation of the group, a more resistant palatal surface may have helped process high-fiber forage. Notably, in cynodonts the secondary palate is also considered a prerequisite for innovations such as higher metabolic rates, endothermy, and suckling behavior, but this level of physiological integration did not occur in therocephalians or anomodonts, which went extinct during the Triassic.

The description of the Choerosaurus palate is a contribution to understanding the initial evolutionary history of synapsid secondary palate development, building on recent comprehensive sampling of the earliest cynodonts. The authors note that future CT-assisted descriptive research targeting other early baurioids and non-dicynodont anomodonts, along with more functional and paleoecological studies, will be needed to understand the selective pressures underlying these changes. For now, a single crushed skull from the Karoo has shown that the road to the mammalian palate was paved more than once, and by different bones each time.

Subject of Research: Paleontology

Article Title: Cranial anatomy of the baurioid therocephalian Choerosaurus dejageri with comments on secondary palate convergence in therocephalians and cynodonts

Article References: Gigliotti, A., Pusch, L. C., Kammerer, C. F., Benoit, J., & Fröbisch, J. (2026). Cranial anatomy of the baurioid therocephalian Choerosaurus dejageri with comments on secondary palate convergence in therocephalians and cynodonts. Frontiers in Mammal Science, 5, Article 1869886. https://doi.org/10.3389/fmamm.2026.1869886

Image Credits: AI Generated

DOI: 10.3389/fmamm.2026.1869886

Keywords: therocephalian, Choerosaurus dejageri, secondary palate, convergent evolution, CT scanning, Permian, therapsids, Lycideopidae, paleontology, Karoo, Cranial, anatomy

The research, conducted by South African specialist in engagement, communication and stakeholder management Anton Binneman, reflects on roughly a decade of meetings with elders and knowledge holders from Indigenous communities descended from the San. The work took shape in the context of the construction of MeerKAT and the development of SKA-Mid, two major telescope projects in the South African Karoo, and formed part of the environmental and social impact assessment required before these facilities could be built. Rather than treating Indigenous knowledge as a static relic to be catalogued, the study set out to understand how it has changed, what has survived, and how it might enter into genuine dialogue with modern science.

One of the central findings challenges a widespread assumption about traditional knowledge: that it is frozen in time, preserved unchanged from some distant past. Binneman’s work demonstrates the opposite. Indigenous narratives, like the communities that tell them, evolve continuously, incorporating new linguistic, religious and social elements, and today even scientific ones. Stories are retold in changing languages, adapted to new circumstances, and reinterpreted by each generation. What survives is not a fixed text but a living relationship with the sky, one that has bent and reshaped itself under the pressures of colonialism, industrialisation and Westernisation without disappearing entirely.

The practical trigger for the research was the international SKA Observatory’s requirement to assess the environmental and social impact of its new telescope. As part of that process, Binneman investigated the ethnoastronomical knowledge of the communities living around the site. To map what remained of this knowledge and how it had transformed over time, workshops were organised in seven locations around the SKA site. These gatherings involved around 52 elders and knowledge holders recognised as such by their own communities, ensuring that the people consulted carried genuine standing and authority in local eyes.

A crucial entry point for these conversations was the Bleek and Lloyd archive, a remarkable nineteenth-century collection that recorded many San narratives, including stories about the sky, in the late 1800s. During the workshops, participants were shown images of celestial objects together with stories drawn from this archive. The prompt was simple and open-ended: tell us what you see and what stories you know about this object. The activities also included evening observations of the sky itself, and when elders were unable to attend the workshops in person, the team conducted home visits and interviews instead, extending the reach of the study beyond the formal meeting rooms.

Binneman is careful to note that the archive could not simply be used as it stood. The collection is strongly shaped by the beliefs of the white researchers who created it at the time, embedding colonial-era assumptions in its very structure. Instead of treating it as an authoritative record of an authentic past, the project used it as a starting point for dialogue with the communities themselves. The archive supplied fragments and prompts; the living memory of the elders supplied meaning, correction and continuity. This methodological choice, treating historical material as a conversation partner rather than a final authority, became a foundation of the approach that emerged from the work.

The findings reveal a highly selective pattern of continuity. Knowledge connected to everyday life has remained far more vivid than complex cosmological narratives. Venus, for example, is still remembered in the region as boer se horlosie, the farmer’s clock, because its appearances in the morning and evening sky traditionally marked the beginning and end of daily activities. This is astronomy in its most practical and durable form, tied to the rhythms of work and survival rather than to abstract theory. It demonstrates how the most functionally embedded elements of sky knowledge resist erosion even as more elaborate narratives fade.

Elsewhere, only fragments have survived. The Milky Way is still called Hemelstraat, the road in the sky, but few people now connect the name with the old |Xam story of the girl who threw ashes into the heavens so that a little light would be made. Binneman observes that older generations still remember these stories, whereas among younger people they are no longer part of living, practised knowledge. Yet this does not mean the stories have simply vanished. They continue to exist, he explains, but their form has adapted in response to colonialism, industrialisation and Westernisation. The narratives persist as cultural material capable of being reawakened, reinterpreted and passed on in new forms.

Out of this decade of engagement grew the Dialogical Knowledge Renewal Model, the study’s central contribution. The approach deliberately does not attempt to recover a supposedly authentic tradition, an idea the research treats as both impossible and misguided given how knowledge actually evolves. Instead, it brings three sources into structured dialogue: historical archives such as Bleek and Lloyd, the living memory of community elders, and contemporary scientific astronomy. Crucially, the model then returns the results of that process to the local area, so that communities benefit directly from the renewed knowledge rather than merely supplying raw material for outside researchers.

The practical outcomes in the Karoo are already visible. The project has contributed to the training of local astronomy guides and to the development of astrotourism in the region, creating economic and educational pathways rooted in the area’s own heritage. But Binneman emphasises that the impact is also symbolic, and perhaps more profound. Recognising the region’s long history of observing the sky helps communities see the SKA not as the arrival of astronomy in a place where it had never existed, but as a new part of their own history. As he puts it, the work restores dignity to people, because the first astronomers were not those who built MeerKAT or the SKA. In the shadow of dishes tuned to the cosmic dawn, the oldest astronomy of the Karoo is being written back into the record.

Subject of Research: Indigenous San ethnoastronomy and cultural memory in the Square Kilometre Array construction area in South Africa

Article Title: The SKA Project: Just the latest chapter in a story thousands of years old

Article References: The SKA Project: Just the latest chapter in a story thousands of years old. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: SKA Observatory, MeerKAT, San people, ethnoastronomy, Indigenous knowledge, Karoo, cultural memory, Bleek and Lloyd archive, science communication, astrotourism, radio astronomy, South Africa