The observational study examined whether biological traits were associated with species’ IUCN conservation status and their exposure to threats recorded in the International Union for Conservation of Nature’s Threats Classification Scheme, version 3.3. Its scope was limited to mammals occurring in Nigeria. Eight threat-specific models covered residential and commercial development, agriculture and aquaculture, energy production and mining, transportation and service corridors, biological resource use, human intrusions and disturbance, pollution, and climate change and severe weather.

The researchers compiled species records and spatial data from the IUCN Red List and matched scientific names against PHYLACINE 1.2 and phylogenetic trees from Upham and colleagues, producing a harmonised list of 314 taxa. Body-mass data came from PHYLACINE, while brain-mass and generation-time data came from the COMBINE database. Geographic range was calculated from IUCN spatial polygons, producing measures of total area, current area and extinct area. Range could not be calculated for 17 primarily aquatic or semi-aquatic species because polygon data were missing.

Five predictors were included in the analysis: absolute current geographic area, the ratio of current to total historical area, body mass, brain mass and generation time. The current-to-total-area ratio was used as a measure of historical range contraction: lower values indicate a greater proportional loss of historically occupied area. This ratio was distinct from the absolute current-range predictor. Threat exposure was coded manually from individual IUCN species profiles, with a value of 1 assigned whenever a threat was listed at any severity or scope and 0 when it was absent.

The researchers used phylogenetic logistic regression to account for shared evolutionary history when estimating trait–risk relationships. They tested combinations of the five predictors, applied variance-inflation-factor diagnostics and excluded combinations with values above 2. Four threat categories with fewer than 25 affected species were omitted because the authors said such samples could produce unstable or overfitted estimates. Nine models were retained: one overall model based on Red List status and the eight threat-specific models.

Brain mass was the most consistent and influential predictor across the models. Larger brain mass was positively associated with estimated extinction risk in the overall analysis and under agriculture and aquaculture, biological resource use, residential and commercial development, and climate change and severe weather. Its largest standardised effects occurred in the climate, development and biological-resource-use models. The authors linked this pattern to characteristics often associated with large-brained mammals, including behavioural specialisation, extended development, delayed reproduction and higher energy demands, as well as possible exposure to hunting and wildlife trade.

Absolute current geographic range was another recurring association. Its effect was negative, indicating higher estimated risk among species with smaller present-day ranges. That relationship was statistically significant under agriculture and aquaculture, biological resource use, human intrusions and disturbance, and in the overall model. By contrast, historical range contraction had limited predictive value. It was significant only in the human-intrusions model, where greater proportional range loss was associated with higher risk, and it was not significant in the overall model or the other threat-specific models.

Generation time also varied by threat. Longer generation times were associated with higher risk under agriculture and aquaculture, energy production and mining, and transportation and service corridors. Under climate change and severe weather, the relationship reversed, with shorter generation times associated with greater risk. The authors proposed that this contrast may reflect differences in sensitivity to environmental variability, although the climate-related effect was weaker than those seen under direct human pressures. Body mass generally had weak effects but was significantly and negatively associated with risk in the agriculture and aquaculture model.

These results indicate that extinction-risk patterns among Nigerian mammals are biologically structured rather than uniform, but the analysis does not establish that the measured traits cause extinction. Its precision is constrained by the resolution and attribution accuracy of IUCN threat records, especially for gradual or indirect threats such as pollution and climate change. Some trait values also required inference or imputation: body mass was directly available for 312 of 314 species, while brain mass and generation time were directly available for 295 species. The estimates also depend on the completeness and accuracy of the phylogenetic tree and taxonomy used. The authors conclude that trait-based, phylogenetically informed evidence could help prioritise large-brained, range-restricted and slow-reproducing mammals and support responses tailored to particular threats.

Subject of Research: Trait-based analysis of extinction risk among 314 mammal species in Nigeria

Article Title: Assessing patterns of extinction risk amongst mammal species in Nigeria: A comparative analysis of human impact

Article References: Asanbe, B. (2026). Assessing patterns of extinction risk amongst mammal species in Nigeria: A comparative analysis of human impact. Biodiversity Data Journal, 14, Article e191439. https://doi.org/10.3897/bdj.14.e191439

Image Credits: AI Generated

DOI: 10.3897/BDJ.14.e191439

Keywords: Nigeria, mammals, extinction risk, phylogenetic regression, brain mass, geographic range, generation time, threat exposure, biodiversity conservation, Assessing, patterns, extinction

The subspecies was described by Joseph Müller in 1903 from Vrbica by Vransko blato, near Vrana Lake in Mediterranean Croatia. Its type material is held in the Civic Museum of Natural History in Trieste, Italy. For the analysis, researchers assembled 82 records collected across the Western Balkans over roughly 130 years: 81 from Croatia and one from Slovenia. The database combined information from scientific publications, 56 entomological-collection records, 10 literature-derived records and four direct field observations. The Global Biodiversity Information Facility contained no records of the subspecies when accessed on 20 January 2025. Records were organized by decade, collection date and biogeographical region, with pre-1975 observations classified as historical and those from 1975 onward classified as recent.

The researchers used a chronogeonemy analysis, which examines the temporal and spatial dimensions of changes in a species’ occupied area, to reconstruct trends in the subspecies’ Croatian distribution. They also compared land cover at Vrbica and nearby Biljane Donje using the Third Military Survey of the Habsburg Empire from 1869 to 1887, CORINE Land Cover data from 1980 and 2018, and chi-squared tests of changes between broad Level 1 and finer Level 3 land-cover categories. A separate gap analysis intersected known Croatian records with national parks, nature parks and Natura 2000 sites under the Habitats and Birds Directives. The combined approaches were intended to assess both historical change and the coverage provided by the current protected-area network.

Only six Mediterranean records were recovered, all from mainland Croatia rather than the Adriatic islands. Three originated in northern Dalmatia near Zadar, including the type locality at Vrbica and Biljane Donje near Vrana Lake; two came from the Istrian Peninsula; and one came from the Draga Valley near Rijeka. The most recent Mediterranean record dates from 1968, while the type locality has produced no record for more than 120 years. The authors interpret this pattern as local extinction rather than simply an absence of observations. Surveys of carabid beetle assemblages in wetland and riparian habitats have repeatedly covered the region, including work around Vrana Lake and on the Istrian Peninsula. At Vrana Lake, more than 85 pitfall traps and hand sampling during the vegetation season failed to detect the subspecies.

Historical maps show that the landscapes supporting the early records no longer resemble the sites where the beetle was found. The nineteenth-century military survey depicts broad marshes around Vrana Lake, including Vransko blato at the type locality. Comparison with CORINE maps showed that the wetland was fully drained and the remaining marshes near the lake were restricted to a narrow strip along its northwestern edge. At Biljane Donje, the former Terljuge wetlands were also drained. Between 1980 and 2018, broad-leaved forest disappeared within the Biljane Donje study area, transitional woodland and shrub declined, and pasture increased. Statistical comparisons identified significant changes in the broad land-cover categories there, with a chi-squared value of 41.45 and p < 0.001, as well as significant changes within the finer categories, all at p < 0.001.

Some of the habitat transformation at Vrana Lake preceded the formal establishment of protected areas. Work on the Prosika Canal lowered the lake’s water level by approximately three metres and allowed water to drain toward the Adriatic Sea. Further canal deepening and a land-reclamation project completed in 1948 subsequently converted most of the surrounding wetland ecosystem to farmland. An ornithological reserve was established at Vrana Lake in 1983, the Vrana Lake Nature Park followed in 1999, and Natura 2000 sites were designated. The authors conclude that these measures came too late to preserve the beetle’s Mediterranean population because the relevant habitat changes had already occurred. The apparent success of protected-area coverage therefore did not correspond to the subspecies’ continued persistence at the type locality.

The Continental region of Croatia presented a different pattern. The subspecies has been recorded there since the late 19th century, with the earliest precisely localized record dating from March 1896 in Osijek. The number of records fell between the two world wars and during the postwar period, then rose sharply from 2000 onward, especially during 2000 to 2010. The authors note that reduced entomological research may partly account for the earlier scarcity of observations, while the more recent increase may also reflect greater sampling effort. Nevertheless, they interpret the pattern alongside the continuing presence of populations as evidence that the large Continental wetlands support the subspecies. Protected areas covered 14 of 16 known Continental localities, or 88%. Across all precisely georeferenced Croatian records considered in the gap analysis, 18 of 22, or 82%, were inside protected areas.

Most recent Continental records come from wetlands along the Sava, Drava and Danube rivers, particularly the Lonjsko polje and Kopački rit nature parks. Both are Ramsar-listed wetlands and among the largest remaining wetland complexes and best-preserved semi-natural habitats in the Danube Basin. The beetle occurs in open wet grasslands, pastures, reedbeds, shrubby vegetation near water and flooded lowland forest. Its ecological requirements are narrow: it is described as stenotopic and highly hygrophilous, and later larval instars and adults hunt underwater. The first larval instar lives on land. Populations include both fully winged and short-winged individuals, and the species is unusual within the genus because it retains the capacity for flight. A single winged specimen recorded on the Mura River in northeastern Slovenia in 2007 was not followed by other finds during intensive monitoring from 2007 to 2024, so the researchers regard it as accidental rather than evidence of an established Slovenian population.

Some habitat within the Continental wetlands is maintained through existing human land use. Livestock grazing and pigs rooting in wet soils create shallow depressions that hold water and form a mosaic of saturated microhabitats. These conditions are associated with the occurrence of the subspecies in Lonjsko polje. The findings do not imply that all human intervention benefits the beetle; rather, they identify grazing and rooting as specific activities that create habitat features used by the insect. The broader wetlands also support other threatened organisms, including the notostracan crustaceans Triops cancriformis and Lepidurus apus and endangered beetles. The authors therefore describe the Golden-dimpled Ground Beetle as a potential flagship and umbrella species for Continental wetland nature parks. Within Croatia, most records occurred below 200 metres, with no records in the Alpine region and none in surveyed peatlands.

The species already has an alarming conservation history elsewhere in Europe. Carabus clatratus is considered highly threatened and has been reported extinct in Switzerland and Italy. In Italy, the spread of the invasive Red Swamp Crayfish, Procambarus clarkii, is associated with predation on adult beetles and contributed to the species’ extinction. The Mediterranean wetlands examined in Croatia have not recorded that crayfish. Based on the beetle’s high reproductive potential and a successful reintroduction in Italy before crayfish invasion, the authors recommend restoring suitable wetland habitat and reintroducing specimens from Continental Croatia, potentially at Vrana Lake, to improve the subspecies’ prospects. More broadly, they call for revised conservation assessments, continued protection of wetlands against drainage, and use of historical distribution analysis alongside modern spatial tools so that protected-area statistics do not conceal extinctions that have already occurred.

Subject of Research: Conservation status and habitat-driven local extinction of the Golden-dimpled Ground Beetle in Croatia and Slovenia

Article Title: Extinction risk alert: evaluating conservation trends for the Golden-dimpled Ground Beetle ( Carabus clatratus auraniensis J. Müller, 1903) in Western Balkans

Article References: Brigić, A., Ružanović, L., Mlinarić, M. K., Vujčić-Karlo, S., Koren, T., Vrezec, A., & Kapla, A. (2025). Extinction risk alert: evaluating conservation trends for the Golden-dimpled Ground Beetle (Carabus clatratus auraniensis J. Müller, 1903) in Western Balkans. Nature Conservation, 59, 257-277. https://doi.org/10.3897/natureconservation.59.161038

Image Credits: AI Generated

DOI: 10.3897/natureconservation.59.161038

Keywords: Golden-dimpled Ground Beetle, Carabus clatratus auraniensis, local extinction, wetland degradation, land-use change, Croatia, Western Balkans, protected areas, chronogeonemy, Vrana Lake, Extinction, risk

The Yumidong Cave sits at about 1100 meters above sea level in the Miaoyu Basin at the northern foot of the Wushan Mountains, roughly four kilometers from the famous Longgupo Cave, a site central to Quaternary paleontology in China. The cave is a horizontal karst feature developed in limestone, and its stratigraphic sections interbed sandy clay with limestone breccia, recording alternating warm and cool phases that researchers have correlated with marine isotope stages from MIS 8 down to MIS 1. Dating results and faunal comparisons place the fossil-bearing layers in the Mid-Late Pleistocene. Flying squirrels rank among the most abundant groups in the mammalian fauna collected there, giving paleontologists excellent material for detailed morphological comparison of a group that has often suffered from misidentification in earlier studies.

The largest and most abundant species in the assemblage is Pteromys volans, the Siberian flying squirrel, a Palaearctic cold-adapted glider that today ranges from northeast Europe to the Korean Peninsula and Hokkaido. Specimens are plentiful in the cave, making up 9 percent of small mammalian fossils in layer ②-2 and a striking 46 percent in layer ④. The mandibles are very short, with length close to height, and carry a particularly marked angular process wider than the ascending ramus. The cheek teeth are brachyodont, with P3 small but bearing differentiated cusps, P4 fully molarised, and M3 lacking a metaloph and metaconule. On lower teeth, the mesoconid and entoconid are permanent, the trigonid basin remains open, and m3 is conspicuously elongated. These features distinguish the Yumidong material from other small Pleistocene flying squirrels of south China, such as Hylopetes electilis with its pitted cheek tooth enamel, and from the Early Pleistocene Pteromys huananensis known only from Longgupo Cave.

Trogopterus xanthipes, the complex-toothed flying squirrel endemic to China, is the second species identified. It still survives in the region today, living from temperate subalpine coniferous forest to subtropical broad-leaved forest at altitudes of 1360 to 2750 meters. The Yumidong mandibles are high and strong, with a deep pterygoid muscle fossa and a vascular notch that is extensive. The upper cheek teeth carry a well-developed mesostyle connecting paracone and metacone, an enlarged metaconule, and numerous cristae dividing the anterior and posterior valleys into several enamel loops. Lower molars develop metalophids and folds in the talonid basin, making the occlusal surface more complex than that of p4. The genus is diagnosed by this complex dentition and by size: Trogopterus is significantly larger than its closest relative Belomys, with almost no overlap in cheek tooth measurements.

Belomys pearsonii, the hairy-footed flying squirrel, is the third species. It is widely distributed today in south China, northeastern South Asia and Southeast Asia, but has completely disappeared from the Wushan area, although subfossils were reported from the Neolithic Dahekou site in Chongqing. The mandible and teeth closely resemble Trogopterus xanthipes, but the species is much smaller and more lower-crowned. Several dental differences separate the two: P3 of Belomys sits closer to the protocone of P4; the protocone of P4-M2 is more developed while the hypocone is weaker; and the hypocone and metaloph of M3 are absent, whereas in Trogopterus the hypocone is permanent and connects with the metaconule by a straight metaloph. Within the genus, the Early Pleistocene Belomys parapearsoni is smaller with a lower crown, and the Thai Late Pleistocene Belomys thamkaewi falls within the size range of Chinese fossil B. pearsonii, so the Yumidong material is confidently assigned to B. pearsonii.

The fourth species, Aeretes melanopterus, is the largest flying squirrel in the assemblage and one of the rarest mammals in China today, confined to the northeastern Qinghai-Tibet Plateau, the Hengduan Mountains, the Qinling Mountains and a small population near Beijing. It inhabits coniferous and broad-leaved mixed forest at 2500 to 3000 meters and nests on high trees. The Yumidong mandible is robust with a short diastemal portion, and the cheek teeth are subhypsodont with slightly rugose enamel, the lingual wall of upper teeth higher than the buccal wall. P4 is molariformed and triangular in outline, with a small protocone separated from the developed hypocone by a vertical anterolingual flexus extending to the crown base. The genus differs from Petaurista, whose M1/2 lacks a hypocone, and the Yumidong specimens fall within the size and morphological variation of the living species, though they are smaller than Pleistocene specimens from the Tianyuan Cave in Beijing.

Reading these four species together as environmental indicators produces a clear paleoecological signal. All four can adapt to coniferous and broad-leaved mixed forest and alpine coniferous forest, but Pteromys volans and Aeretes melanopterus are cold-adapted Palaearctic species that have completely vanished from the study area and its vicinity. Both were excavated mainly from layer ②-2 and layer ④, the cool phases correlated with MIS 2 and MIS 4, and neither appears in layers ③ and ⑤, the warm phases of MIS 3 and MIS 5. The conclusion is that during MIS 2 and MIS 4 the area around Yumidong Cave was dominated by subalpine evergreen coniferous forest or coniferous and broad-leaved mixed forest, colder and richer in conifers than today, resembling the vegetation now found on Wushan peaks above 2000 meters. During MIS 3 and MIS 5 the landscape was similar to the present subtropical environment.

The regional extinction of the cold-adapted species follows a pattern the authors trace through the glacial-interglacial cycle. Cold-adapted flying squirrels spread southwards during glacial periods and disappeared from the area during interglacials. They likely occupied the middle zone of the Wushan Mountains during the latest Pleistocene or the Last Glacial Maximum, but when the Holocene Megathermal arrived, their habitats contracted to higher peaks. Those limited ecological spaces could not sustain viable populations, and the squirrels died out regionally. Nearby caves reinforce the picture of vertical zonation controlling faunal divergence: Baotansi Cave at about 820 meters shares the same species combination, while Migong Cave at only 160 to 200 meters records a cool but sparser forest with no flying squirrel fossils at all, showing that altitude differences within the same period produced different habitats across the Three Gorges area.

The study also corrects earlier records that seemed to show cold-adapted flying squirrels surviving into the Holocene. Re-examination of material from the Dahekou Neolithic site in Fuling District shows that specimens originally identified as Trogopterus xanthipes should be Belomys pearsonii, that the records of Petaurista petaurista and Aeretes melanopterus appear to be an undetermined Petaurista species, and that the material called Hylopetes alboniger actually belongs to the subfamily Sciurinae and resembles Tamiops swinhoei. Current evidence therefore cannot demonstrate that Pteromys volans, Trogopterus xanthipes or Aeretes melanopterus persisted from the Last Glacial through the Holocene in the Three Gorges area, sharpening the extinction timeline for the cold-adapted fauna.

With four species of four genera identified from abundant maxillae, mandibles and isolated teeth, Yumidong Cave now stands as one of the richest flying squirrel localities of the Chinese Quaternary, and the detailed morphological descriptions set a new standard for a group long neglected in Pleistocene faunal lists. The assemblage demonstrates how a single cave sequence can track the interplay between climate oscillation, vertical mountain zonation and regional extinction. As ice ages deepened, coniferous forest climbed down the slopes and cold-adapted gliders followed; as warmth returned, the forest retreated upward and the squirrels with it, until the Holocene Megathermal pushed their refugia beyond the limits of survival. The fossil teeth of Yumidong thus preserve not just species but the rhythm of forests rising and falling across the mountains of the Three Gorges.

Subject of Research: Pleistocene flying squirrel fossils from Yumidong Cave, China

Article Title: Fossil flying squirrels ( Petauristinae , Sciuridae , Rodentia ) from the Yumidong Cave in Wushan County, Chongqing, China

Article References: Pang, L.-B., Chen, S.-K., Hu, X., Wu, Y., & Wei, G.-B. (2024). Fossil flying squirrels (Petauristinae, Sciuridae, Rodentia) from the Yumidong Cave in Wushan County, Chongqing, China. Fossil Record, 27(1), 209-219. https://doi.org/10.3897/fr.27.115693

Image Credits: AI Generated

DOI: 10.3897/fr.27.115693

Keywords: flying squirrels, Yumidong Cave, Pleistocene, paleoenvironment, China, Fossil Record, extinction, Petauristinae, Fossil, flying, squirrels, Sciuridae

Can Llobateres 1, excavated on and off since the 1940s, is one of the most thoroughly sampled Vallesian sites in Europe. It is best known for yielding the remains of Hispanopithecus laietanus, a late-surviving great ape that hung from the fig trees and laurels of a marshy, humid forest. But the site’s pig fossils have had a messier history. The small tetraconodontine Parachleuastochoerus crusafonti, named from this very locality, dominates the sample. Three other species, however, were reported from a handful of teeth in the early 1970s and then shuffled, dropped, and re-added by successive generations of faunal lists, often without descriptions, measurements, or even photographs to back them up.

The new revision, led by researchers at the Institut Català de Paleontologia Miquel Crusafont, went back to the drawers. The team re-examined the original specimens described in the 1970s and, crucially, dug through decades of unpublished material recovered during later excavation campaigns in 1981, 1990, and the 2010s. The result is the first detailed, illustrated, and measured account of every identifiable suid tooth from Can Llobateres 1 that does not belong to its namesake species. It confirms that the site’s pig community really did contain four species, and it corrects several long-standing misidentifications along the way.

The most consequential confirmation concerns Listriodon splendens, a large, lophodont pig with blade-like teeth adapted for shearing leaves. Listriodontines were among the most successful suid groups of the Middle Miocene, but their diversity collapsed during the late Miocene. The Can Llobateres 1 record, dated to roughly 9.8 million years ago by magnetostratigraphy, now stands as the last well-dated occurrence of the species anywhere in Europe. The evidence comes from five deciduous teeth, most likely belonging to a single juvenile, recovered during the 1981 campaign and never described until now. Their distinctive morphology, from compressed spatulate incisors to kidney-shaped premolars, matches Listriodon splendens so closely that the authors rule out any alternative assignment.

That last-appearance datum matters because it helps time the extinction of an entire subfamily. Listriodon splendens had already vanished from East Asia and eastern Europe millions of years earlier, clinging on only in western European refugia. Its presence at Can Llobateres 1 shows it survived the whole of the early Vallesian before disappearing, a pattern that paleontologists suspect was driven by rising seasonality and competition with rooting pigs that could fall back on underground food stores when fruit and foliage grew scarce.

The second confirmed species is Propotamochoerus palaeochoerus, a suine pig represented at the site by a remarkable concentration of juvenile remains: unworn milk molars, tooth germs still sealed inside their crypts, and two mandibular fragments that almost certainly belonged to one young individual. A single isolated premolar previously attributed to Parachleuastochoerus crusafonti has been reassigned to this species, and the associated material, labeled with catalog numbers from the later excavations, finally puts published reports of the species at the site on solid ground. Dental topographic analyses from earlier work classify Propotamochoerus palaeochoerus as an omnivorous generalist, an opportunistic feeder with the trophic flexibility to exploit resources well beyond the wetland forest floor.

The third species is the most taxonomically fraught. A large tetraconodontine pig, bigger than the abundant Parachleuastochoerus crusafonti, was tentatively reported in the 1970s as Hyotherium soemmeringi, a name that has since been carved up across multiple genera. Decades of nomenclatural dispute followed, with competing authors splitting and lumping the European tetraconodontines into Versoporcus, Conohyus, and Parachleuastochoerus, sometimes assigning different teeth from the same jaw fragment to different species. The new study cuts through this by comparing the Can Llobateres 1 material, including a distinctive lower first premolar and three incisors, against published samples from across Europe. The verdict: the large pig is ‘Parachleuastochoerus’ valentini, a species kept in quotation marks precisely because paleontologists still cannot agree which genus it truly belongs to.

That open nomenclature is more than academic fussiness. The genus question hinges on the anatomy of Parachleuastochoerus crusafonti itself, whose type species still lacks described cranial remains, and on whether the features distinguishing ‘Pa.’ valentini, such as the absence of a cementum band on the male lower canine and reduced premolar proportions, evolved once or in parallel. A recent cladistic analysis found that neither ‘Pa.’ valentini nor its rival Versoporcus steinheimensis sits close to Parachleuastochoerus crusafonti, leaving the large pig’s family tree genuinely unresolved. What the new study does establish is biochronological: ‘Pa.’ valentini outlived Versoporcus steinheimensis, surviving the entire early Vallesian alongside the last listriodontines.

The proportions of the assemblage tell an ecological story. Of 239 suid teeth from the site, 86 percent belong to the small, rooting Parachleuastochoerus crusafonti, while the other three species together account for barely 14 percent, with ‘Pa.’ valentini known from just four teeth. That imbalance fits the site’s paleoenvironmental reconstructions, built from fossil plants, mammal communities, and dental ecometrics, which paint Can Llobateres 1 as a densely forested, humid wetland ringed by more open woodlands. The dominant pig, equipped with high-crowned, heavily worn incisors and rooting behavior, could thrive year-round in the humid core, digging up roots and tubers when the monsoon-like rainy season gave way to lean months. The rarer generalists likely ranged into the drier, more open habitats nearby, visiting the forest only opportunistically.

Seen in full, the revised assemblage captures a community at its ecological tipping point. Within a few hundred thousand years, the Mid-Vallesian Crisis would prune the forest-adapted fauna of Europe, and the listriodontines, already down to their final species, would be gone entirely. The pigs of Can Llobateres 1, from the abundant rooter to the leaf-shearing specialist making its last stand, record the moment before the fall, one carefully measured tooth at a time.

Subject of Research: Taxonomic revision of the Late Miocene suid assemblage from Can Llobateres 1, Spain

Article Title: The suid assemblage from the Vallesian locality of Can Llobateres 1 (Vallès-Penedès Basin, NE Iberian Peninsula) revisited

Article References: Arranz, S. G., Siarabi, S., McKenzie, S., Casanovas-Vilar, I., & Alba, D. M. (2026). The suid assemblage from the Vallesian locality of Can Llobateres 1 (Vallès-Penedès Basin, NE Iberian Peninsula) revisited. Swiss Journal of Palaeontology, 145, 267-291. https://doi.org/10.3897/sjp.145.183361

Image Credits: AI Generated

DOI: 10.3897/sjp.145.183361

Keywords: paleontology, Miocene, suids, Can Llobateres 1, Vallès-Penedès Basin, Listriodon splendens, Parachleuastochoerus, Vallesian, extinction, paleoecology, Spain, fossil pigs

The story began with the American botanist Elmer Drew Merrill, who in August 1917 collected a single individual of a beautyberry shrub in thickets along a small stream at roughly 900 meters elevation on Luofu Mountain. Merrill described the plant as a new species, Callicarpa oligantha, in 1918, noting its alliance with C. dichotoma but distinguishing it by its longer, narrower leaves, subsessile and abaxially pubescent foliage, shorter filaments, and cymes bearing very few flowers. Crucially, his description rested on a single gathering from one individual. For nearly 110 years afterward, no additional plants matching that description were ever documented, and the species drifted into taxonomic limbo, categorized as data deficient in China’s national Red List and never assessed by the IUCN.

Doubts about the species’ validity surfaced early. In his 1951 review of the Chinese species of Callicarpa, Chang considered C. oligantha closely allied to C. brevipes and suggested it might merely represent a morphological variant of that species. The problem was that no one could test the idea, because there was nothing to test: no fresh material, no living plants, no DNA. That changed when a field survey at Luofu Mountain rediscovered a population of Callicarpa closely matching Merrill’s original description, with one notable exception. Some individuals bore pubescent fruits and occasional hairs on the lower leaf surfaces, traits absent from the protologue, likely because Merrill had only ever seen a single specimen from a single plant.

Armed with newly collected material, the research team launched an integrative taxonomic reassessment combining molecular phylogenetics with statistical morphological comparisons. For the genetic work, they sampled five individuals of C. oligantha from the type locality and three individuals of C. brevipes from Guangdong, Hainan, and Vietnam, embedding them within a broad phylogenetic frame of twenty Callicarpa species, with two Australian outgroup taxa anchoring the analysis. Total genomic DNA was extracted from silica-dried leaf tissue using the CTAB method, and the team amplified and sequenced two nuclear ribosomal regions, nrITS and nrETS, together with eight chloroplast DNA markers previously shown to be effective for resolving relationships in this genus.

The analytical strategy was deliberately conservative. To reduce potential bias in phylogenetic reconstruction, the researchers applied both concatenation-based and coalescent-based methods. Maximum likelihood analyses with 5,000 ultrafast bootstrap replicates and Bayesian inference sampling five million trees were run on concatenated datasets totaling 1,087 base pairs of nuclear ribosomal DNA and 7,435 base pairs of chloroplast DNA. A multispecies coalescent approach in StarBEAST2 was used to infer species trees, accounting for incomplete lineage sorting, a process that can seriously mislead standard tree-building methods. The results were unambiguous: Callicarpa oligantha was intermingled with C. brevipes in both nuclear and plastid datasets, with strong statistical support, and the coalescent species trees recovered C. oligantha as sister to C. brevipes. In other words, the ‘extinct’ species is not an evolutionarily independent lineage but part of the variation within C. brevipes.

The morphology told the same story. The team measured six characters regarded as key for distinguishing Callicarpa species: leaf length, leaf width, petiole length, inflorescence width, inflorescence branching, and filament length, using ImageJ software on both the new collections and historical type specimens, including the isotype of C. oligantha preserved at the United States National Herbarium and the lectotype of C. brevipes at Kew. Principal component analysis of leaf morphology explained 91.4 percent of the variance in the first two axes, and flower morphology 94.6 percent, with C. oligantha and C. brevipes forming a single cluster in every analysis. T-tests found no significant differences between the two in any of the measured characters. The ranges overlap almost completely: leaf length spans 8.5 to 14.5 centimeters in C. oligantha versus 8.4 to 17.5 centimeters in C. brevipes, and the two species share the same lanceolate to narrowly lanceolate leaf blades. The distributions of the two taxa also overlap entirely across southeastern China and Vietnam.

Based on this congruent molecular and morphological evidence, the authors formally propose synonymizing C. oligantha under C. brevipes, following Article 11 of the International Code of Nomenclature for Algae, Fungi, and Plants, the Shenzhen Code. As part of the taxonomic treatment, they also designated a lectotype for C. brevipes, a Champion specimen at Kew that matches the original description, untangling a complicated nomenclatural history that stretches back to Hooker’s 1825 misidentification of a living Chinese plant as Callicarpa longifolia. The rediscovered population, once a candidate for urgent protection as a last-of-its-kind survivor, is now understood to be a population of a species assessed as least concern, with stable populations and no major threats across its range in Guangdong, Guangxi, Hainan, Hong Kong, and Vietnam.

The implications reach far beyond one shrub. The study joins a growing body of evidence showing how shaky taxonomy can distort conservation priorities. The authors point to Fagus chienii, a beech designated as a key protected species in 2016 despite being known from a single 1935 collection, only for molecular work to reveal it is conspecific with F. hayatae. They also cite Torreya grandis var. jiulongshanensis, once listed as a Category II protected plant, which phylogenetic study showed to be a natural hybrid rather than a distinct lineage. Perhaps most striking is the clover fern Marsilea azorica, managed as critically endangered under the Bern convention and the European Union’s habitats directive, until researchers demonstrated it was conspecific with an invasive species and recommended its removal from every conservation list it occupied.

For Callicarpa oligantha, the practical consequences were immediate and concrete. Local forestry authorities had been likely to include the species in the list of key protected wild plants, directing substantial conservation effort toward a name rather than a genuinely unique lineage. The new study recommends excluding C. oligantha from extinction lists, freeing those resources for species facing real threats. The authors note that the only other plant assessed as probably extinct in Guangdong, the mycoheterotroph Corsiopsis chinensis, remains a genuinely enigmatic case, known from an unusual specimen collected in 1999 and not observed in field surveys since.

The broader lesson is one that conservation biology keeps relearning: accurate species delimitation is the foundation on which every red list entry, protected area decision, and recovery plan ultimately rests. When species boundaries are drawn from single specimens or superficial resemblance, limited resources can flow toward phantom extinctions while genuinely endangered lineages go unprotected. The researchers emphasize that robust taxonomic frameworks, ideally built on integrative, multidisciplinary evidence combining DNA sequences, morphology, and fieldwork, must be established before conservation action is taken. They also call for population genomic studies with expanded sampling across the full distribution of C. brevipes to reveal patterns of intraspecific genetic diversity that single-locus phylogenies cannot capture. A century-old enigma has been closed, an extinction has been un-declared, and a small purple-fruited shrub on a mountain in South China has become an unlikely poster child for the quiet, essential science of taxonomy.

Subject of Research: Integrative taxonomic reassessment of the supposedly extinct plant Callicarpa oligantha and its synonymy with Callicarpa brevipes

Article Title: Rediscovery and reexamination of a declared 'extinct' plant in South China: The species delimitation and conservation implications of Callicarpa oligantha ( Lamiaceae )

Article References: Cai, H., Yang, Q., Xu, Y., Tu, T., & Ma, Z. (2026). Rediscovery and reexamination of a declared 'extinct' plant in South China: The species delimitation and conservation implications of Callicarpa oligantha (Lamiaceae). PhytoKeys, 278, 157-176. https://doi.org/10.3897/phytokeys.278.203604

Image Credits: AI Generated

DOI: 10.3897/phytokeys.278.203604

Keywords: Callicarpa oligantha, Callicarpa brevipes, taxonomy, species delimitation, rediscovery, extinction, conservation, phylogenetics, Guangdong, Lamiaceae, biodiversity, red list

The story begins in 1889, when legendary fossil hunters John B. Hatcher and Charles E. Beecher collected a partial skeleton from the Lance Formation of what is now Niobrara County, Wyoming. The specimen, cataloged as YPM 295 at the Yale Peabody Museum, is remarkably complete by the standards of fossil softshell turtles: it preserves most of the plastron, a large portion of the carapace, remains of all four limbs, and significant parts of the neck and tail. In 1904, paleontologist Oliver Hay named it Aspideretes beecheri, describing its shell surface as a network of ridges enclosing rather deep pits. Among North American fossil pan-trionychids, the group that includes modern softshell turtles and their closest extinct relatives, this is one of the most complete type specimens ever recovered.

Just four years later, Hay established a second species from the same formation, Helopanoplia distincta, based on two shell fragments decorated with distinct tubercles that occasionally coalesce into ridges. Despite the scant nature of its type material, this species quickly became one of the most frequently cited turtles from the latest Cretaceous of North America. Its unique tuberculate surface texture proved so recognizable that hundreds of specimens, mostly fragments, were referred to it from the Lance Formation of Wyoming, the Hell Creek Formation of Montana, North Dakota, and South Dakota, the Ferris Formation of Wyoming, and the Denver Formation of Colorado. Yet something strange happened with Aspideretes beecheri: over the entire course of the twentieth century, not a single new specimen was ever referred to it, even as softshell turtle fossils poured out of the same formations.

The new study set out to solve this conundrum by re-examining all material historically associated with both names. The researchers observed every specimen in person, documented them with digital photography, and scanned select fossils with a portable Artec Space Spider surface scanner, with the resulting three-dimensional models made publicly available on MorphoSource. To assess how much variation a single species can display, they compared the fossil material with extant trionychids, the living softshell turtles whose shells are known to change dramatically in texture and callosity coverage as individuals grow.

The verdict on the old specimens was sweeping. All specimens historically referred to Aspideretes beecheri were reassigned to two other species, Axestemys splendidus and Axestemys infernalis. This includes the paratype of Aspideretes beecheri, a partial carapace whose netted texture and relatively large posterior costals match Axestemys infernalis, as well as a previously unmentioned partial skeleton, YPM 3755, which had been quietly cataloged under the old name at the Yale museum. An unusual plastron from the Hell Creek Formation that had been referred to Helopanoplia distincta was instead reassigned to Hutchemys walkerorum, a species named only in 2022.

But the holotype itself told a different story. When the team compared YPM 295 with complete carapacial and plastral material referred to Helopanoplia distincta, including a near-complete carapace from the Hell Creek Formation of North Dakota cataloged as NDGS 353, the similarities proved overwhelming. Both specimens share a coarse, netted texture pattern topped by fine tubercles at the intersections, anteroposteriorly deep nuchal processes fully covered by the nuchal callosity, a preneural element in the neural column, a second costal that expands distally at the expense of the first, and a dramatic reduction of the seventh and eighth costals, which jointly contribute no more to the shell margin than the sixth costal alone. The estimated midline lengths of the two carapaces, roughly 33 and 39 centimeters, differ by only about 20 percent.

The few differences that do exist between these specimens, the researchers argue, are best explained by ontogeny, the changes that occur as an animal matures. In living softshell turtles, the costal bones increasingly cover the free rib ends and laterally surround the nuchal callosity as individuals grow, a process that occurs early in some species and remarkably late in others. The near-complete carapace from North Dakota, being the larger of the two, shows exactly the more advanced coverage pattern that would be expected in an older individual. Similar logic applies to the plastron: fragments from Montana that are about 30 percent larger than the holotype display callosities that expand further medially and form pronounced anterior lappets, features that in extant trionychids develop only in mid-sized and older individuals. Even the striking variation in surface texture among the referred fragments, ranging from isolated tubercles to finely netted patterns, falls within the intraspecific variation documented in living species.

The taxonomic mechanics of the merger follow the rules of zoological priority. Because Aspideretes beecheri was named in 1904, four years before Helopanoplia distincta, the older name takes precedence as the senior synonym. However, paleontologists going back to the 1990s agree that no fossil turtle from the Cretaceous to Paleogene of North America actually belongs to the extant southern Asian genus Aspideretes, so the species must be moved into Helopanoplia, whose type species is distincta. The result is the new combination Helopanoplia beecheri, a name that is fortuitously close to what the species has been called colloquially all along. The researchers also urge caution for anyone identifying fragmentary softshell turtle remains, because a tuberculate surface texture pattern is now known to occur in at least two distinct taxa, including Axestemys infernalis, meaning texture alone can no longer be trusted as a species-level identifier.

The reassessment carries real consequences for one of paleontology’s most famous extinction stories. The Cretaceous-Paleogene boundary, 66 million years ago, wiped out the non-avian dinosaurs and, as decades of collection-based studies have shown, most turtles of the latest Cretaceous survived into the Paleocene. Helopanoplia distincta, however, has long been cited as one of only a few turtle species to have gone extinct at the boundary, a conclusion drawn from the complete absence of its telltale tuberculate shell fragments in early Paleocene deposits. Because so much leeway was previously given when identifying tuberculate textures, the new study views those older results with skepticism, and many unfigured fragments previously assigned to the species may actually represent Axestemys infernalis instead.

Yet the extinction conclusion itself survives the taxonomic housecleaning. The literature unanimously agrees that tuberculate shell fragments are absent from the early Paleocene, and phylogenetic analyses have so far failed to identify any plausible descendant of Helopanoplia beecheri in Paleocene faunas. The evidence, the researchers conclude, remains sufficient to establish that this species did not survive the extinction event. After more than a century of confusion, one of the last softshell turtles of the Age of Dinosaurs finally has a coherent identity, a clearer fossil record, and a confirmed place among the rare turtle casualties of the asteroid impact that ended the Mesozoic world.

Subject of Research: A reassessment of the latest Cretaceous (Maastrichtian) pan-trionychid turtle Helopanoplia beecheri comb. nov.

Article Title: A reassessment of the latest Cretaceous (Maastrichtian) pan-trionychid turtle Helopanoplia beecheri comb. nov.

Article References: Joyce, W. G., Girard, L. C., & Lyson, T. R. (2026). A reassessment of the latest Cretaceous (Maastrichtian) pan-trionychid turtle Helopanoplia beecheri comb. nov.. Swiss Journal of Palaeontology, 145, 665-677. https://doi.org/10.3897/sjp.145.189487

Image Credits: AI Generated

DOI: 10.3897/sjp.145.189487

Keywords: paleontology, turtles, Cretaceous, extinction, taxonomy, reassessment, latest, Maastrichtian, pan-trionychid, turtle, Helopanoplia, beecheri

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 scale of the loss is hard to overstate. The Imperial Woodpecker, Campephilus imperialis, was the largest woodpecker on record, stretching more than 60 centimetres from bill to tail tip. It depended on the vast, mature pine forests of northwestern Mexico, a habitat that was largely logged away, and the species is now presumed extinct. Around 100 preserved specimens exist in museums worldwide, and the only moving images of the living bird consist of a few seconds of grainy film shot in 1956. In other words, almost everything the public knows about how this bird looked and moved comes from a handful of static skins and a flicker of archival footage. The new digital specimen aims to change that by translating those fragile remains into a form anyone can access and share.

The reconstruction began, as so many museum science projects do, with a drawer in a collection. The team worked from a female specimen held at the Moore Laboratory of Zoology in Los Angeles, which houses the world’s largest collection of Mexican birds. To capture the bird’s true shape, the researchers photographed the specimen 288 times from every conceivable angle and applied photogrammetry, a technique that converts overlapping photographs into a precise three-dimensional surface. The resulting digital body captured the specimen’s form with sub-millimetre accuracy. Throughout the process, the team took careful measurements of the head, bill, body, wings and tail to make sure the digital bird remained faithful to the physical original rather than drifting into artistic approximation.

The feathers turned out to be the hardest part of the entire project. On a century-old museum skin, individual feathers are difficult to distinguish, let alone digitise. The researchers solved this by modelling individual feather shapes on those of the Pileated Woodpecker, the largest living woodpecker in North America and the Imperial’s closest available analogue, then resizing and adjusting them to match the known proportions of the Imperial Woodpecker. Wing patterning was drawn from scientific illustrations and checked against the available visual record. In the final model, ten primary feathers, ten secondary feathers and twelve tail feathers were each individually modelled and rigged, meaning each one can spread, bend and fold independently in response to the underlying animation.

Once the body and plumage were in place, the team turned to open-source software called Blender to build a digital skeleton that drives the model’s movement. This armature sits beneath the photogrammetric surface and articulates the wings, tail and feathers through space, much as a real skeleton and musculature would. To the team’s knowledge, the result is one of the first open, specimen-based bird reconstructions to combine a photogrammetric body with individually animated feathers — a technical milestone that could set a template for future digital avatars of extinct and rare species. Every component of the workflow, from the scan data to the rigged feathers, was designed to be shared rather than locked away.

Two animations bring the model to life. The first is a looping flight sequence showing the bird with its wings fully extended, the second a short clip of the bird climbing a tree trunk and drumming against the bark, the behaviour for which woodpeckers are best known. Neither animation was invented from thin air. Both are grounded in the 1956 film footage of the living species, supplemented by behavioural video of the Pileated Woodpecker and published data on woodpecker wingbeat timing. That combination of historical film, comparative footage and quantitative data gives the animations a level of scientific grounding that separates this digital specimen from simple artistic reconstructions.

Beyond its visual appeal, the model is designed as a reproducible scientific resource. Researchers can use it to estimate the bird’s body volume and surface area, compare its shape with living relatives, or run simulations of flight and feather movement. The authors also note that such a model could inform the design of bird-inspired flying robots, an emerging field where realistic wing geometry and articulation matter enormously. Because the model is open and downloadable, other scientists can scrutinise it, adapt it and improve it as new evidence emerges, rather than relying on a single frozen visual interpretation of the species.

The team is candid about the limits of the reconstruction. It is based on a single female specimen, which means it cannot capture variation between sexes or among individuals. Aspects such as soft tissue and flight kinematics rely on informed estimation from living relatives, since no Imperial Woodpecker exists to observe directly. The researchers hope that future work will digitise further specimens from museum collections to build a fuller picture of the species as it once was. They also frame the project as a proof of concept: a small team, modest resources and a museum skin proved sufficient to produce a scientifically useful, publicly available digital specimen.

There is also a cultural dimension to the work. The Imperial Woodpecker features in the traditions of Indigenous communities of the Sierra Madre Occidental, yet few, if any, museum specimens of the species are actually held in Mexico. The authors suggest that freely shared digital models may help offset these geographic and institutional barriers, allowing people in the bird’s native range to encounter a faithful representation of a species their landscapes once supported. At the same time, they acknowledge that whether such digital repatriation can genuinely contribute to the return of biological and cultural heritage remains an open question, one that digital specimens alone cannot answer.

Perhaps the most striking point the researchers make is about public memory. The Imperial Woodpecker might be the last bird species to have gone extinct in continental North America, yet by their estimate the overwhelming majority of people have never heard of it. If a digital specimen can raise awareness of extinct species by even a fraction of a percent, they argue, that translates into millions of people gaining a concrete sense of what extinction can erase from the planet. The model, skeleton and animations are available to view and download through Sketchfab, turning a drawer-bound museum skin and a few seconds of 1956 film into a permanent, shareable encounter with one of the most spectacular birds ever to have lived.

Subject of Research: Digital 3D reconstruction of the extinct Imperial Woodpecker from museum specimens and historical film

Article Title: Imperial Woodpecker returns to life as a detailed digital specimen

Article References: Imperial Woodpecker returns to life as a detailed digital specimen. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Imperial Woodpecker, 3D model, photogrammetry, extinct species, museum specimens, Blender, feather articulation, digital specimen, Sierra Madre Occidental, Natural History Collections and Museomics, ornithology, extinction

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

The research, published in the journal The Holocene, reconstructs the immigration history and extinction dynamics of the Scandinavian aurochs, Bos primigenius, using a combination of ancient DNA, radiocarbon dating and osteological analysis. The team extracted genetic material from aurochs bones recovered from bogs and archaeological settlement sites across southern Sweden and Denmark, then tracked how the frequency of dated specimens and the number of bones at archaeological sites changed over time. By comparing the age composition of the bones at different sites and relating the results to regional palaeoenvironmental and archaeological records, the researchers were able to piece together a timeline of arrival, isolation and decline that differs in important ways from what scientists had previously assumed.

The story begins around 11,700 years ago, at the close of the last Ice Age, when aurochs first began colonising Scandinavia as the ice sheets retreated and new land opened up for grazing animals. What the researchers discovered about that colonisation surprised them. As the animals moved north from mainland Europe up through the Jutland peninsula and then across Zealand and Scania, their genetic diversity did not stay constant. Instead, it dropped steadily with each step northward, a pattern the team interprets as a severe population bottleneck suffered during the migration itself. The aurochs that reached Scandinavia were therefore a genetically impoverished subset of the wider European population from the very start, carrying far less of the variation that helps species weather environmental change.

“I found it incredibly interesting to see how the genetic diversity of the aurochs decreased as you moved north from mainland Europe up through Jutland and then dropped further across Zealand and Scania. It’s a textbook example of a bottleneck in evolutionary genetics,” says Mikkel-Holger S. Sinding, associate professor at the University of Copenhagen and a senior author of the study. In evolutionary terms, a bottleneck occurs when a population passes through a phase in which only a small number of individuals contribute to the next generations, stripping out genetic variation. For a large-bodied species with naturally low population densities, such a loss of diversity can have consequences that persist for millennia, reducing fertility, increasing vulnerability to disease and limiting the ability to adapt to shifting climates and habitats.

One of the study’s most significant revisions concerns when the Scandinavian aurochs became isolated from their continental relatives. It had previously been believed that the population was cut off around 10,000 years ago, early in the postglacial recolonisation. The genetic evidence tells a different story. The Scandinavian aurochs remained in contact with the main European population well beyond that date, with genes continuing to flow across the connection between the two regions. True isolation came only when the land bridge linking Scandinavia to the European mainland was finally flooded around 8,000 years ago, an event that created the Danish-Swedish straits and severed the population for good. From that moment, the aurochs of southern Scandinavia were on their own, a small, genetically depleted group with no possibility of reinforcement from the healthier populations to the south.

The timing of that isolation proved fateful in another way as well. The formation of the straits coincided with a period of apparently intense human hunting, and the archaeological record shows a sharp decline in the Swedish aurochs population during this window. On the island of Zealand in Denmark, the pressure was even more decisive: the aurochs disappeared from the island completely. For a species already squeezed by low genetic diversity, the combination of rising seas cutting off escape routes and human hunters targeting the remaining animals appears to have pushed local populations past the point of recovery. The study thus reframes the Scandinavian extinction not as a single catastrophic event but as a cascade of pressures arriving in quick succession.

Even so, the aurochs did not vanish from the entire region immediately. In southern Sweden, a remnant population persisted in low numbers until at least 6,500 years ago, hanging on for some fifteen centuries after the straits formed. What finally finished them off, the researchers argue, was a change in the landscape itself. The open, park-like environments that aurochs favoured after the Ice Age gradually gave way to dense forests as the climate warmed and woodland spread across the region. This shift is thought to have been detrimental to the species, which depended on more open habitats for grazing. Habitat fragmentation and degradation, layered on top of genetic depletion and continued human pressure, closed the last chapter of the aurochs in Scandinavia thousands of years before the species finally blinked out in Poland.

“These ancient case studies reveal long-term patterns – which species are most vulnerable, how ecosystems shift and transform over time, and when and how human activity began shaping these environments,” says Erika Rosengren, a doctoral student in historical osteology at Lund University and lead author of the paper. The research team concludes that it was the combined effects of genetic depletion, human pressure, habitat fragmentation and habitat degradation that set the Scandinavian extinction in motion, a more intricate set of causes than the simple human-overexploitation narrative that had dominated earlier thinking. The finding matters because it demonstrates that even a large, widespread and ecologically flexible species can be driven to regional extinction when several stressors overlap, each one individually survivable but collectively lethal.

The implications reach well beyond the aurochs. As Rosengren points out, the results add nuance to the understanding of human impact on animal populations and confirm that species rarely disappear because of a single factor. Conservation plans, she argues, must therefore be comprehensive and consider multiple stressors at the same time, rather than focusing on one threat in isolation. The study also lends scientific weight to a specific practical recommendation: the establishment of ecological corridors for threatened wildlife, rather than relying on isolated nature reserves. The fate of the Scandinavian aurochs, trapped on a newly isolated peninsula with depleted genes, shrinking habitat and persistent hunting, is a vivid illustration of why connectivity between populations can be as important as protecting the animals themselves.

In that sense, an extinction that unfolded more than six millennia ago speaks directly to the present. Many of today’s threatened large mammals face the same stacked pressures: small and fragmented populations, shrinking genetic diversity, habitat loss and continuing human exploitation. The aurochs, whose domestic descendants now number more than a billion animals worldwide, offer a rare and unusually well-documented case study of how those pressures interact over thousands of years. By combining ancient DNA from bog-preserved bones with radiocarbon chronologies and archaeological assemblages, the Lund-led team has shown that the earliest regional extinction of Europe’s wild cattle was neither sudden nor simple, but a slow-motion collision of genetics, geography and human ambition whose lessons conservationists are still learning to apply.

Subject of Research: The extinction dynamics of the Scandinavian aurochs reconstructed through ancient DNA, radiocarbon dating and archaeological evidence.

Article Title: Study sheds new light on why aurochs disappeared in Scandinavia

Article References: Study sheds new light on why aurochs disappeared in Scandinavia. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: aurochs, Scandinavia, ancient DNA, population bottleneck, extinction, Holocene, habitat fragmentation, conservation, Lund University, Bos primigenius, ecological corridors, zooarchaeology