The site first came to scientific attention in January 2004, when a palaeontologist from the local municipality reported bones weathering out of the ground near the fishing village of Cauca, about 14.6 kilometres northwest of the town of Urumaco. Systematic work had to wait until 2021, when researchers secured permits and launched three excavation seasons across five work areas. The fossiliferous zone covers roughly 1,600 square metres, with eight distinct groupings of bones identified on the surface. Because the bone-bearing layer is only about 40 centimetres thick, excavations were shallow but productive, recovering 41 cranial and postcranial elements now housed in the palaeontological collection of the Urumaco municipality.

The geology of the site tells a story of environmental change. Today the region is semi-arid, buffeted by trade winds and receiving as little as 200 millimetres of rain per year. Yet the oxidation patterns and fine silt-clayey sands that hold the fossils suggest Cauca was deposited in a low-energy, more humid environment, possibly a swampy patch or intermittent body of water. During the Late Pleistocene, the coastal plains of Falcón suffered a negative water balance, and nearby sites such as Muaco and Taima-Taima are interpreted as resurgent springs that formed oases attracting animals during dry spells. Cauca may have offered a similar lifeline, explaining why so many different species died and were buried in one small area.

The star of the assemblage is a giant megatheriine ground sloth assigned to cf. Eremotherium laurillardi, a species that ranged from the southeastern United States to Brazil and could weigh several tonnes. Excavation Cauca B yielded fourteen disarticulated elements, including a partial skull 580 millimetres long, a right hemi-mandible with all four molariform teeth, a complete right radius of 700 millimetres, a clavicle, vertebrae, a metatarsal and part of a pelvis. The researchers believe these bones belong to a single adult individual. A key measurement supported the identification: the ratio of mandible depth below the third tooth to the length of the tooth row came out at 0.77, squarely within the 0.73 to 0.83 range characteristic of Eremotherium.

Other South American natives round out the megaherbivore roster. A thick, short right radius recovered in the same excavation differs markedly from the sloth’s slender radius and is attributed to an indeterminate mylodontid, another family of ground sloths. Two eroded shell osteoderms represent glyptodonts, the tank-like armoured relatives of armadillos, probably related to the genus Glyptotherium, which is well known from other Falcón sites. These finds extend the known geographic distribution of several taxa and reinforce the picture of Falcón as a Pleistocene hotspot where xenarthrans thrived from sea level to mountain areas above 1,200 metres.

The Nearctic contingent of the fauna is equally significant. A mandible with well-preserved molars, a tusk measuring about 1.7 metres long and scattered dental fragments document the gomphothere Notiomastodon platensis, the elephant-like proboscidean that was South America’s last native megaherbivore of this lineage. Wear patterns on the molars and the robust, uncurved, enamel-free tusk distinguish it from the only other South American gomphothere genus, Cuvieronius. An unworn upper second molar found a few metres from one excavation hints at the presence of a juvenile animal. Extinct horses add to the picture: a nearly complete lower third molar shows the occlusal features of Equus, though the researchers conservatively label it Equus sp. because the taxonomy of South American fossil horses remains contested.

Perhaps the most unexpected specimen is a small right ankle bone, an astragalus just over 23 millimetres long, identified as Felidae cf. Leopardus pardalis, the ocelot or cunaguaro. Fossil records of medium-sized cats in the northern neotropics are exceedingly scarce, and this is the first report of the species from northwestern Venezuela. The researchers compared the astragalus with modern specimens of ocelots and bobcats, noting that the bone’s proportions align more closely with Leopardus pardalis than with Lynx rufus, which has never been recorded in South America. An earlier claim of a Pleistocene bobcat-like cat at the nearby Muaco site was never illustrated and cannot be confirmed, making the Cauca astragalus a rare and valuable data point for understanding felid biogeography.

Dating the site required careful laboratory work. Because no bone collagen survived, the team isolated tooth enamel from a gomphothere mandible and a horse tooth, grinding the samples to fine powder and pre-treating them with acetic acid to remove contaminating diagenetic carbonates. Accelerator mass spectrometry produced ages of 33,750 plus or minus 350 years for the gomphothere and 37,050 plus or minus 500 years for the horse, which calibrate to roughly 37,500 to 39,500 and 41,300 to 42,300 calendar years before present respectively. These are among the oldest dates ever produced on bioapatite and sit near the practical limit of radiocarbon dating. Because enamel can exchange carbon with soil carbonates and appear artificially young, the researchers emphasise that the true age of the deposit is likely greater than 40,000 years.

Lithic artefacts found near the excavations add an archaeological dimension, though with important caveats. A chopper, a planoconvex scraper and flakes were recovered on the surface adjacent to the dig areas, and between 100 and 150 metres northeast of the site, prospecting has revealed El Jobo, Clovis and Fish Tail projectile points, technologies associated with the region’s early hunter-gatherers. However, none of these artefacts was found in direct stratigraphic association with the fossils, and decades of laminar erosion have stripped away the upper layers, possibly mixing materials of different ages. The team therefore treats any link between humans and the Cauca megafauna as speculative, in contrast to nearby sites such as Taima-Taima and El Vano, where stone points have been found genuinely associated with butchered gomphothere and sloth remains.

Taphonomic analysis explains both what was found and what was lost. Surface bones had reached the most advanced stage of weathering, fragile and crumbling, while excavated specimens preserved in the second layer retained enough integrity for recovery and plaster-jacketing. The spatial arrangement of the sloth remains, scattered across three excavation areas over roughly a dozen metres, breaks with the anatomical pattern expected in high-energy transport, suggesting the carcass disarticulated in place under low-energy conditions. The scarcity of large, dense limb bones such as humeri and femurs may reflect decades of destruction before the site was documented. Despite these limitations, Cauca joins a growing network of Venezuelan Pleistocene localities along the Coro coastal plain, interpreted as a natural corridor that channelled faunal and human movements during the Great American Biotic Interchange, and it underscores how much of the continent’s Late Pleistocene story, from giant sloths to elusive ocelots, still lies waiting in thin layers of tropical sand.

Subject of Research: Late Pleistocene megafaunal and felid fossils from the new Cauca site in northwest Venezuela

Article Title: Cauca: megafaunal and felid fossils ( Mammalia ) from a Pleistocene site in northwest Venezuela

Article References: Carrillo-Briceño, J. D., Ruiz-Ramoni, D., Sánchez, R., Jaimes, A., Chávez-Aponte, E., Prevosti, F. J., Segura, V., Carlini, A. A., Garbé, L., Tombret, O., Zazzo, A., & Sánchez-Villagra, M. R. (2024). Cauca: megafaunal and felid fossils (Mammalia) from a Pleistocene site in northwest Venezuela. Fossil Record, 27(1), 187-207. https://doi.org/10.3897/fr.27.119967

Image Credits: AI Generated

DOI: 10.3897/fr.27.119967

Keywords: Pleistocene, megafauna, Venezuela, Falcón State, Eremotherium, Notiomastodon, Equus, Leopardus pardalis, glyptodont, radiocarbon dating, paleontology, Gulf of Venezuela

The dispute is old. Discussions about what killed off the megafauna stretch back to the late eighteenth and early nineteenth centuries, when early naturalists first grappled with the realization that entire suites of enormous animals had disappeared from continents where humans and fossils coexisted. Over more than two centuries, the debate has cycled through hypotheses implicating rapid climate swings at the end of the Pleistocene, the spread of anatomically modern humans and their hunting technologies, disease, comet impacts, and combinations of these forces. What began as an argument among archaeologists and paleontologists has, in recent decades, drawn in ecologists and conservation biologists, who see the late Quaternary extinctions as a natural experiment with direct lessons for how modern ecosystems might be managed, restored, or even rewilded.

That expansion has brought energy and expertise, but it has also brought a problem. Dozens of papers on the topic appear each year, and alongside them a steady stream of review articles. Yet, as the authors of the new study note, these reviews tend to reflect the viewpoints of their authors, filtering the literature through particular disciplinary lenses and, sometimes, particular conclusions. A paleontologist’s synthesis may weigh evidence differently than an archaeologist’s or an ecologist’s, and readers are left without an objective map of the terrain. Recognizing this limitation, the research team set out to build a data-driven overview of the entire debate, treating the published literature itself as the object of study.

The approach was systematic in the strict sense. Rather than selecting studies that support a favored hypothesis, the researchers assembled and analyzed the literature in a structured way designed to minimize bias. Their goals were threefold: first, to trace how the megafauna extinction debate has developed and evolved over time; second, to identify the key thematic and conceptual foci within the body of work; and third, to use that synthesis of historical trends and interdisciplinary variation to propose a forward-looking research agenda. The aim of the agenda is not to declare a winner in the extinction debate but to encourage greater engagement, discussion, integration, and collaboration across the many fields that now touch the question.

The analysis surfaced three major findings. The first is that strong disciplinary divides persist. Researchers trained in different fields frame the problem differently, favor different lines of evidence, and often publish in separate venues, with the result that key arguments circulate within disciplinary silos rather than across them. The second is that research coverage is uneven in both time and space. Some regions and some periods of the late Quaternary have been intensively studied, while others remain comparatively neglected, leaving the global picture built on a patchy foundation. The third is that despite decades of work and major methodological advances, uncertainty over the causes of the extinctions remains persistent. The debate has not converged; it has, in some respects, become more intricate as new data and new techniques have multiplied the possible interactions among climate change, human pressures, and species biology.

The methodological evolution of the field is itself striking. Over the past several decades, researchers have deployed increasingly advanced analytical and statistical methods to the extinction question. Dating techniques have sharpened chronological frameworks, allowing the timing of megafauna losses to be compared against the timing of human arrival and climatic transitions with growing precision. Statistical modeling has been used to test competing extinction hypotheses against empirical patterns, and ancient DNA has opened windows into population histories of extinct species. Yet the systematic review shows that these advances have not dissolved the disagreement. Instead, the field remains fragmented, with methodological sophistication coexisting alongside conceptual division.

Why does the fragmentation matter? The stakes extend well beyond academic scorekeeping. Ecologists and conservation biologists increasingly view the late Quaternary extinctions as a lens through which to inform contemporary conservation and ecosystem management strategies. If the causes of those ancient losses are misread, the lessons drawn for modern conservation may be distorted as well. Understanding whether climate, humans, or their interaction drove past megafauna declines shapes how scientists think about the vulnerability of today’s large mammals, many of which face comparable pressures of habitat loss, hunting, and rapid environmental change. The extinction debate is, in this sense, not merely about the past; it is a live input into decisions about the future of ecosystems worldwide.

The forward-looking research agenda proposed by the study responds directly to the fragmentation it documents. The authors call for greater interdisciplinary collaboration, arguing that the strongest progress will come when archaeologists, paleontologists, ecologists, geologists, and statisticians work from shared datasets and shared frameworks rather than parallel conversations. They also emphasize the need to expand field and legacy studies, which means both new excavations and surveys and the reanalysis of existing museum collections and previously published data with modern methods. Species-specific approaches receive particular attention: rather than treating megafauna as a monolithic category, the agenda urges researchers to examine how individual species with different body sizes, reproductive rates, habitats, and histories responded to the pressures of the late Quaternary.

Integration of cutting-edge scientific and statistical techniques rounds out the proposed agenda. The review suggests that the field’s next phase should combine advanced modeling, improved chronological control, and interdisciplinary data synthesis in ways that explicitly test competing hypotheses rather than accumulating evidence for favored ones. The researchers frame this as a way to foster engagement and discussion across fields, converting the debate’s long history of disagreement into a structured program of collaborative inquiry. The emphasis on discussion and integration reflects the study’s core message: the extinctions are too complex, and the evidence too scattered across disciplines, for any single field to resolve the question alone.

What emerges from the systematic review is a portrait of a debate that has endured for more than two centuries because the underlying problem is genuinely hard. The late Quaternary extinctions unfolded across multiple continents, under varying climatic regimes, alongside human populations at very different stages of technological development, and among species with widely varying ecologies. Disentangling those threads requires the combined strengths of many disciplines, sustained fieldwork in understudied regions and periods, and analytical methods capable of handling the interactions among multiple potential drivers. The new study does not settle the extinction debate, and it does not claim to. Instead, it offers the field something arguably more valuable: an objective, data-driven account of where the debate stands, where its blind spots lie, and how researchers across disciplines might move forward together. For a question that has resisted resolution since the age of Cuvier, that may be the most important contribution yet.

Subject of Research: Megafauna Extinction Debate Systematic Review

Article Title: The state of the late Quaternary megafauna extinction debate: a systematic review and analysis

Article References: Stewart, M., Peters, C., Ziegler, M. J., Carleton, W. C., Roberts, P., Boivin, N., & Groucutt, H. S. (2025). The state of the late Quaternary megafauna extinction debate: a systematic review and analysis. Frontiers in Mammal Science, 4, Article 1678231. https://doi.org/10.3389/fmamm.2025.1678231

Image Credits: AI Generated

DOI: 10.3389/fmamm.2025.1678231

Keywords: megafauna, extinction, late Quaternary, systematic review, paleontology, archaeology, conservation biology, Pleistocene, mammoths, interdisciplinary research, state, late

The team, led by Leyi Fang, Dongsheng Zhang, Chengcheng Shen and Chunsheng Wang of the Second Institute of Oceanography in Hangzhou, together with colleagues at Shanghai Jiao Tong University, Zhejiang Ocean University and Beijing Pioneer Hi-Tech Development Corporation, deployed seafloor imaging across a broad gradient of nodule cover in a Northwest Pacific nodule province. From the thousands of photographs, the researchers annotated a total of 169 morphospecies belonging to 14 phyla. Holothurians, the elongated sea cucumbers that plow through abyssal sediment, and sponges, the stationary pumpers of deep water, emerged as the dominant taxa, together anchoring the community structure of this remote ecosystem.

The surprise came when the researchers quantitatively assessed how megafaunal density responded to nodule cover. Rather than a monotonic rise, density declined from low to intermediate nodule cover, remained relatively stable across intermediate levels, and then increased sharply at high cover. The U-shaped response suggests that the relationship between nodules and abyssal animals is far more nuanced than the widely held assumption that more hard substrata automatically mean more biodiversity. At low cover, the seafloor community is dominated by mobile deposit-feeders, animals such as holothurians that ingest sediment and extract organic particles from it. At high cover, the balance flips decisively toward sessile filter-feeders, sponges and other attached organisms that strain suspended particles from the water column.

Technically, the transition is driven primarily by changes in the relative density of dominant taxa rather than by species turnover. In ecological terms, the same cast of characters persists across the nodule gradient, but their relative abundances shift dramatically, producing a pronounced change in community composition. This distinction matters for how scientists model and predict the impacts of deep-sea mining. If nodule removal primarily alters the balance of dominant species rather than eliminating rare ones outright, the ecological consequences of mining may manifest first as functional shifts in how the ecosystem processes carbon and nutrients, rather than as immediate extinctions.

The study also placed the Northwest Pacific nodule province in a global context by comparing it with the Clarion-Clipperton Zone, the vast fracture zone in the eastern Pacific that has become the epicenter of deep-sea mining interest. The comparison revealed that the Northwest Pacific supports lower megafaunal density and a distinct assemblage composition, yet achieves comparable diversity. The researchers attribute these large-scale differences to two oceanographic variables: the flux of particulate organic carbon, the rain of organic particles from the surface that feeds abyssal life, and carbonate saturation, which governs whether animals can build and maintain calcium carbonate structures. Both variables exert continental-scale influence on abyssal biogeography, meaning that nodule provinces cannot be managed as interchangeable units.

Polymetallic nodules form over millions of years as metal oxides precipitate around nuclei on the seafloor, growing at rates of millimeters per million years. Because they provide the only hard substrata across abyssal plains, they are widely assumed to enhance biodiversity, and this assumption has shaped environmental baselines for mining contracts. Yet, as the authors note, understanding of how nodule cover shapes megafaunal communities has remained limited, largely restricted to conditions of low nodule cover. By sampling across a broad gradient, the new study fills a critical gap, revealing that the ecological role of nodules changes qualitatively as cover increases, not just quantitatively.

The implications for deep-sea mining are direct. The International Seabed Authority has yet to finalize mining regulations, and environmental management of nodule provinces has often relied on region-wide assumptions drawn from the better-studied Clarion-Clipperton Zone. The new findings underscore the need for region-specific management, since the Northwest Pacific responds differently to nodule cover and hosts a distinct community composition. Mining scenarios that remove nodules from high-cover areas would disproportionately affect sessile filter-feeders, organisms that cannot relocate once their substratum is gone. Conversely, areas of low cover dominated by mobile deposit-feeders may respond to mining disturbance through different mechanisms, such as sediment plume effects on feeding and movement.

The research was conducted aboard the research vessel Dayangyihao, with cruises organized and supported by Beijing Pioneer Hi-Tech Development Corporation. Species annotation benefited from consultation with specialists in deep-sea taxonomy, and the statistical framework was refined through iterative analysis. The work was financially supported by the National Key Research and Development Program of China, the Scientific Research Fund of the Second Institute of Oceanography under the State Key Laboratory of Submarine Geoscience, and the UN Ocean Decade Programme Digital DEPTH, reflecting the growing international investment in abyssal ecosystem science ahead of anticipated mining decisions.

As demand for battery metals intensifies and the prospect of commercial nodule extraction moves closer, studies like this one provide the ecological evidence base that regulators and mining companies will need. The U-shaped density response and the mobile-to-sessile community transition reveal that nodule cover is not a simple biodiversity dial but a structural driver that reshapes how abyssal ecosystems function. Protecting the full range of nodule cover conditions, from sparse to dense, may therefore be essential to preserving the ecological integrity of the Northwest Pacific abyss, one of the least explored and most consequential frontiers in ocean science.

Subject of Research: Deep-sea megafaunal ecology and polymetallic nodule cover in the Northwest Pacific abyss

Article Title: Pronounced megafaunal community transition driven by polymetallic nodule cover in the Northwest Pacific abyss

Article References: Fang, L., Zhang, D., Shen, C., Pang, Y., Lin, S., Yan, R., Li, R., Li, H., & Wang, C. (2026). Pronounced megafaunal community transition driven by polymetallic nodule cover in the Northwest Pacific abyss. Communications Earth & Environment. https://doi.org/10.1038/s43247-026-04042-5

Image Credits: AI Generated

DOI: 10.1038/s43247-026-04042-5

Keywords: deep-sea mining, polymetallic nodules, abyssal plain, megafauna, Northwest Pacific, benthic ecology, Clarion-Clipperton Zone, holothurians, sponges, marine biodiversity, Pronounced, megafaunal

The research was led by Kelly Graf, professor of anthropology at the University of Kansas, who co-wrote the paper with Ted Goebel, KU professor of anthropology and department chair, doctoral student Mia Harbort, undergraduate Mason Sewing, and other colleagues from the United States and Europe. Graf began traveling to the site in 2013 and returned every year until the COVID-19 pandemic interrupted fieldwork, with subsequent seasons in 2021, 2023 and 2025. As director of the excavation project, she secured several National Science Foundation grants totaling 400,000 dollars to support the work. The effort has yielded more than 80,000 archaeological specimens, an assemblage that includes a unique hafted-biface form, tools made from bone and antler, a diverse array of animal remains, and remarkably well-preserved activity areas where ancient camp tasks can still be read from the ground.

To understand why the site matters, it helps to picture the world of the late Pleistocene. The Bering Land Bridge formed about 35,000 years ago, when sea levels dropped far enough to expose the continental shelf between Siberia and Alaska, and it remained above water until rising seas submerged it around 12,000 years ago. During that window, a region larger than many modern countries served as both a corridor and a homeland. Today the area around the Shég’ Xdaltth’i’ site is cloaked in spruce forest, but during the final millennia of the Ice Age it was covered in shrub-tundra vegetation, a cold, open landscape in which hardy plants, large herbivores and the people who hunted them coexisted along the Tanana River, one of the major river systems of interior Alaska.

The faunal record from the site shows that its residents were skilled hunters of Ice Age megafauna. Mammoth, bison and horse, all three of which are now extinct, appear in the assemblage alongside caribou, a species that survives today and remains a critically important resource for Indigenous communities across Alaska. Graf noted that caribou has always been a vital resource for the region’s Indigenous peoples, a continuity that stretches back to the very occupations her team has excavated. The combination of extinct and extant prey in a single site illustrates the breadth of the late-glacial subsistence economy and the flexibility hunters needed to survive in a subarctic environment where seasons were extreme and resources patchy.

Among the most evocative discoveries is a large stone anvil found within a dwelling feature. Around it, the excavators found bison bones that had been deliberately broken apart, along with numerous quartz and quartzite hammerstones, the tools used to fracture the bone. Graf explained that the pattern suggests people were using these stones to fully process the bones in order to extract marrow and likely to render grease, a calorie-rich food product that would have been essential in a northern winter. All of this activity, she said, was taking place near a large earth oven, a heated pit used for slow cooking. Together, the anvil, the hammerstones, the shattered bones and the oven preserve a frozen moment of camp life: a group processing an animal carcass into fat and marrow, likely sharing the results around a hearth.

Other key finds point to the sophistication of the site’s inhabitants. Bird bones were fashioned into needles, evidence of tailored clothing sewn from hides, an indispensable technology for people enduring Ice Age winters in a treeless landscape. The team also recovered numerous diamond-shaped bifacial points, which Graf suggested may have served as the sharpened tips of weapons. The shape is distinctive: she said it is the only site in Alaska that features this clear diamond form, and the only other places from this period with such points in a northern context lie on the Russian side of the land bridge. That distribution carries a striking implication. As Graf put it, it suggests people traveled across the Bering Land Bridge to, and possibly from, this location, making the site a potential waypoint in the back-and-forth movements that ultimately populated two continents.

Technically, the site contributes to a long-running debate about how and when humans moved from Asia into the Americas. Beringian archaeological occupations are concentrated in an area only slightly larger than the U.S. state of Maryland, which makes each well-documented site disproportionately valuable. The three components at Shég’ Xdaltth’i’, separated by roughly a thousand years, span the transition from the late-glacial period into the early Holocene, capturing what researchers describe as settling-in behavior: the process by which newly arrived populations learned the geography, established recurring camps, and developed the toolkits and food-processing strategies suited to a far northern setting. The presence of a dwelling feature, organized activity areas and repeated occupations indicates that this was a base camp, a place to which people returned, rather than a brief hunting stop.

The publication, titled “Highlights from an early base camp in Beringia 13,800 years ago: Shég’ Xdaltth’i’ and the Late Pleistocene Peopling of Alaska,” appears in Science Advances, a peer-reviewed journal. The research is an observational study of the archaeological record, and the authors declare no competing interests. For Graf, who has been at the University of Kansas since 2022 and specializes in Ice Age archaeology, environmental archaeology and the peopling of the Americas, the fascination began in an undergraduate North American archaeology class. She recalled falling in love with the Bering Land Bridge concept: people hunting megafauna and traveling from one massive continent to another across exposed continental shelf, studying extinct animals and the tools hunters used to take them. She described getting caught up in the wonder of that vision.

Beyond the individual artifacts, Graf frames the work as part of a larger effort to understand human evolution and adaptation. What began as a mere handful of individuals in a small region has expanded to more than 8 billion people in a fraction of geological time, a trajectory she finds remarkable given humanity’s meager beginnings as hunter-gatherers. Studying how early Beringians coped with the exigencies of Ice Age life, she argues, informs how humans have always adapted and responded to challenges. The more we learn about the evolution of the Homo sapiens species, she said, the more we can understand ourselves today. In that sense, the broken bison bones, the sewing needles and the diamond-shaped points on an Alaskan ridge are not just relics of a distant past but evidence of the problem-solving capacities that carried our species across a vanished land bridge and, eventually, around the entire world.

For now, the Shég’ Xdaltth’i’ site stands as one of the clearest windows into the lives of the people who stood at the threshold of the Americas nearly 14,000 years ago. Its 80,000-plus specimens continue to be analyzed, and each field season adds detail to the picture of a community that hunted mammoth and caribou, rendered grease from bone beside earth ovens, sewed tailored clothing with bone needles, and carried weapon technology across a land bridge that no longer exists. The name given to the site by Alaska Native Athabascan speakers, “they were there,” proves an apt summary of what the archaeology shows: a resilient group of hunter-gatherers, present on that ridge through centuries of change, leaving behind the material record of how they lived.

Subject of Research: Late Pleistocene archaeology of a 13,800-year-old base camp in Beringia, Alaska, and its evidence for the peopling of the Americas

Article Title: Bering Land Bridge base camp reveals what life was like nearly 14,000 years ago

Article References: Bering Land Bridge base camp reveals what life was like nearly 14,000 years ago. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Bering Land Bridge, Beringia, Alaska archaeology, Shég’ Xdaltth’i’, Pleistocene, megafauna, hunter-gatherers, peopling of the Americas, Tanana River, Science Advances, University of Kansas, late-glacial

The research, led by former UC Santa Barbara postdoctoral researcher Courtney Reed, now at Princeton University, and published in the Proceedings of the National Academy of Sciences, combined measurements of soil chemistry, microbial communities, plant biodiversity and herbivore activity at elephant carcass sites. Senior author Deron Burkepile, a professor of ecology, evolution and marine biology at UC Santa Barbara, and senior author Dave Thompson, a biodiversity scientist at the South African Environmental Observation Network, guided the project as it grew from an opportunistic observation into one of the most holistic studies of terrestrial mega-carcasses conducted to date. The findings reveal a decomposition cascade that simultaneously energizes an ecosystem and reduces its diversity, an unusual combination that challenges assumptions about how large animal remains influence land-based food webs.

The project traces its origins to 2009, when one of Kruger National Park’s great tuskers, a large lone bull elephant named Alexander, died of natural causes near a main road. Thompson, who frequently traveled that route for another project, watched the carcass decompose over the course of a few months and became curious about what it was doing to the ground below. He shared his observations with Burkepile, and the two began developing hypotheses about effects on soil, knock-on consequences across the food web and how those effects might change over time. Early explorations quickly showed how dynamic carcass sites could be, and the pair soon enlisted Kruger’s rangers to help locate sites and applied for grants to study the phenomenon in earnest.

The immediate physical impact of an elephant’s death is dramatic. According to Reed, the carcass initially wipes out all the biomass at its center, leaving a large bare patch. The animal’s immense bulk flattens vegetation, and the traffic of scavengers scrapes the surrounding ground clean. Burkepile describes the effect as a reset of the plant community to zero. Co-author Izak Smit, a senior scientist at South African National Parks, admitted that his intuition had been the opposite of what the data showed. Because the carcass is physically present for only a relatively short period, he expected its ecological effect to be muted and transient. When the laboratory results came back, a very different picture emerged.

That picture centers on an extraordinary pulse of nutrients. Decomposing elephant remains percolate nitrogen and other compounds into the soil, altering soil chemistry and restructuring the microbial community. Reed had suspected nutrient levels would be elevated beneath a carcass, but the magnitude astonished her. At very fresh carcass sites, soil nitrogen concentrations can reach up to 3,000 times higher than surrounding levels, a figure she described as simply insane. Co-author Tercia Midzi, a senior manager in scientific services at Kruger National Park, remarked that that amount of ammonium was not on her bingo card. Counterintuitively, the initial spike does not stimulate regrowth. Rather than acting like spilled fertilizer, the influx of compounds such as ammonium creates nutrient toxicity that prevents plants from growing back at first.

Below ground, the nutrient flood transforms microbial life. Burkepile describes the microbes at an elephant carcass as sprinting, with their metabolism cranking. Activity rises sharply, but diversity falls, likely because a small number of fast-growing species come to dominate the site. Once the soil chemistry mellows somewhat, the plant community follows a similar trajectory. The researchers observed biodiversity coldspots dominated by just a handful of fast-growing species, a pattern that persisted for at least eight years after an elephant’s death. The same cascade that fuels microbial and plant vigor therefore actively suppresses the variety of life at the site, an outcome the team did not anticipate when the work began.

Above ground, however, the story is one of attraction rather than avoidance. Grasses colonizing carcass sites are exceptionally nutritious, based on the team’s assays of grass leaves. Burkepile compares the transformation to turning grasses from watery iceberg lettuce into juicy romaine. Those plants probably grow faster, but herbivores mow them down eagerly because they want access to the nutrient-rich forage. Grazers continued to revisit carcass sites for years after death, and their manure further enriched the soil, creating a feedback loop that keeps nutrient levels elevated. To disentangle grazing from intrinsic regrowth, the team installed fenced exclosures that keep herbivores out of some carcass sites, and they hope to publish the results of that experiment within the coming year.

Burkepile believes savannas may occupy a Goldilocks zone in which carcasses exert particularly strong influence. In more dynamic ecosystems such as forests or wetlands, heavy rainfall may leach nutrients out of the topsoil and wash them away, shortening the effect. Deserts, by contrast, may be too water-limited for microbes and plants to exploit the nutrients a carcass provides. The team is seeking collaborators across sub-Saharan Africa to test these hypotheses and intends to keep surveying Kruger’s carcass sites to build a longitudinal time series. They also plan to examine how extreme weather shapes these processes. Kruger experienced exceptionally high rainfall in the past year, and the 2026–27 El Niño is expected to dry the region considerably. Floods and drought can each redirect where nutrients end up, whether percolating into the ground, washing away or preventing growth altogether.

The researchers draw a natural comparison to whale falls, the sunken remains of giant whales that trigger explosions of activity and productivity on the seafloor. Burkepile initially expected elephant carcasses to operate similarly, creating unique islands of ecosystem processes and biodiversity. But the abyssal plain is not the savanna. The deep sea is essentially a food desert, so nutrient-poor and energy-poor that whale carcasses attract organisms from far and wide. Kruger, by contrast, is reasonably fertile, so the nutrient dump from an elephant creates a hotspot so intense that it suppresses microbial and plant diversity rather than enhancing it. Speed differs too. While parts of a whale carcass can persist for decades, even a huge animal like an elephant can lose its meat and bones within a couple of weeks under the African sun. Whale falls have been studied since the late 1970s, but research on terrestrial mega-carcasses is young, with most studies published in the past five years and none previously examining the impacts as comprehensively.

The endurance of the signal surprised the team most. Even around eight years after death, the signature remained detectable in soil and vegetation, and herbivores still preferentially visited those areas. Grazing intensity and nitrogen levels in grasses showed no decline at the oldest sites the researchers surveyed, and the reduced microbial and plant diversity had not rebounded. Smit called it a powerful reminder that what we see in nature is often shaped by legacies from the past, even when their causes have long since disappeared from view. The implications extend deep into history. Elephants and their relatives ranged across most continents until a few millennia ago, living and dying alongside other megafauna. This study shows that what has been lost is not only the influence of living giants but also their posthumous effects. As Smit notes, researchers can only speculate about ecosystems where these mega-herbivores are now missing, but the Kruger findings make those questions far more pressing. What began as two curious scientists with clipboards has become an interdisciplinary effort spanning microbes, soils, plants, herbivores, predators and whole ecosystems, supported by rangers who record elephant mortalities and even creative collaborators producing a documentary, ensuring that the hidden legacy of dead elephants reaches both science and the public.

Subject of Research: Ecological legacy effects of elephant carcasses on savanna soil chemistry, microbial and plant communities, and herbivore grazing in Kruger National Park

Article Title: Elephants continue to shape the savanna even after death

Article References: Elephants continue to shape the savanna even after death. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: elephants, savanna ecology, nutrient hotspots, carcass decomposition, soil microbiome, Kruger National Park, plant biodiversity, herbivore grazing, whale falls, megafauna, nitrogen cycling, PNAS

What makes the discovery extraordinary is the humble nature of the evidence. The species was not identified from a complete skeleton, a horn core, or any diagnostic morphology at all, but from small bone fragments that could not be assigned to any known animal by sight. This is a remarkable discovery of a large extinct species based on small non-diagnostic bones, says Love Dalén, senior author of the study and Professor of Evolutionary Genomics at the Centre for Palaeogenetics. Only through the extraction and sequencing of ancient DNA preserved within the fragments could the team determine that the bones belonged to an animal unknown to science.

The remains were recovered from Denisova Cave and other sites in southern Siberia, a region that has become one of the most important windows into the Ice Age world. By analysing ancient DNA from the unidentifiable fragments, the researchers succeeded in generating twenty ancient genomes spanning an astonishing 200,000 years of evolutionary time. Datasets of this temporal depth are exceptionally rare in ancient DNA research, and they allow scientists to track how populations changed across entire glacial cycles rather than merely sampling a single moment in the past. When the team compared these genomes with those of other bovine species, the result was unambiguous: the fossils belonged to a lineage entirely distinct from any bovine described to date.

The genomic comparisons allowed the researchers to estimate when this mysterious lineage split from its closest living relatives. According to their analysis, the species began diverging from modern yaks around 400,000 years ago and became fully separated around 250,000 years ago. A useful comparison for when this lineage originated is the divergence between brown bears and polar bears, which has also been estimated to have occurred around 400,000 years ago, says Alexandre Gilardet, one of the lead authors and a PhD student at the Centre for Palaeogenetics. This age overlaps with a particularly strong warm climatic period, which could have prompted population isolation and, ultimately, speciation. In other words, a prolonged warm interval may have fragmented ancestral yak populations, cutting groups off from one another long enough for them to evolve into separate species.

The parallel with another landmark discovery from the very same landscape is striking. Denisova Cave is already world-famous as the site where, in 2010, DNA analysis of a single finger bone fragment revealed the Denisovans, an entire group of archaic humans previously unknown to science. These findings mirror the discovery of the Denisovans, a group of archaic humans, from a single fossil in 2010 and highlights the Altai region as a possible biodiversity hotspot and refugium across Ice Ages, says Dalén. The idea that the Altai Mountains and surrounding areas served as a refugium, a place where populations survived through climatic extremes and diversified in isolation, gains considerable weight from the fact that two entirely new branches of the tree of life, one human and one bovine, have now been identified from the same region largely through genetic rather than anatomical evidence.

Yet the new bovine species appears to have had a very different evolutionary history from the Denisovans in at least one crucial respect. When different groups of archaic humans met in Eurasia, they frequently interbred, leaving traces of hybridization in the genomes of their descendants, including present-day people. In contrast, the scientists detected negligible evidence for interbreeding between the new species and other bovines living in the area at the time, such as the steppe bison or the aurochs, the extinct wild ancestor of domestic cattle. This reproductive isolation reinforces the conclusion that the animal was a genuinely separate species rather than a regional population or hybrid lineage, and it suggests that biological boundaries between these large Ice Age herbivores remained firmly in place even when their ranges overlapped.

The deep genomic time series also captured dramatic changes within the species itself. The results suggested that a population replacement occurred during the last interglacial warm period, accompanied by a loss of genetic diversity. This could reflect the genetic consequences of climate warming around 120,000 years ago on a cold-adapted species, says Jonas Oppenheimer, the other lead author of the study and a postdoctoral researcher at the Centre for Palaeogenetics. The long time span of our dataset is really rare in ancient DNA, and allows us to look across whole glacial cycles to see how they might have impacted biodiversity. The last interglacial, a period when global temperatures were warmer than today in many regions, appears to have squeezed cold-adapted fauna into smaller refugia, eroding their genetic variation and reshuffling populations in ways that left permanent signatures in their DNA.

The timeline of the species’ disappearance remains only loosely constrained. The youngest specimen analysed in the study is around 27,000 years old, placing the animal squarely within the last Ice Age, at a time when mammoths, woolly rhinoceroses, steppe bison and other megafauna still dominated the Siberian landscape. The species became extinct sometime after that point, but the exact timing and the causes of its demise remain unknown. Whether it succumbed to rapid climate warming at the end of the Pleistocene, to the spread of humans through the region, to competition with other large herbivores, or to some combination of these pressures is a question that future discoveries may help to answer.

Geographically, the extinct relative of modern-day yaks was detected at Denisova Cave and in the broader Altai-Sayan Mountains and southern Siberian region. The contrast with its living relatives is telling: modern wild yaks are today restricted to the high elevations of the Tibetan Plateau, where they survive in some of the most extreme cold environments on Earth. The new findings suggest that yak-like bovines once occupied a much broader distribution across mid-latitude Asia, and that southern Siberia harboured a distinct lineage that has since vanished without leaving any obvious trace in the fossil record as traditionally studied.

A formal species name, however, must wait. Genetic evidence alone is not sufficient to formally classify and name a new species under the rules of zoological nomenclature, which require comparison with diagnostic physical material. Going forward, the researchers therefore plan to compare their genomic findings with previously described yak-like remains from the region, in the hope of determining whether any of those fossils belong to the same species. If a match is found, the scattered bones in museum collections could suddenly acquire a new identity, and the ghost bovine of the Altai could finally receive both a name and a face. For now, the discovery stands as a powerful demonstration of how ancient DNA can reveal entire species hidden inside fragments too small and too degraded for traditional identification, and as a reminder that even the best-studied Ice Age ecosystems still hold surprises waiting in the sediment.

Subject of Research: Ancient DNA analysis of Ice Age bovine remains from Siberia revealing an extinct yak-relative species

Article Title: Previously unknown extinct bovine species discovered in Siberia

Article References: Previously unknown extinct bovine species discovered in Siberia. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: ancient DNA, bovine, yak, Siberia, Denisova Cave, Ice Age, extinction, speciation, Altai Mountains, palaeogenetics, Current Biology, megafauna