This study presents the first accurate record of the toxodontid Toxodon platensis in the Late Pleistocene of the San Luis Province, central-western Argentina. The specimen, CHN-UNLC-PV 7, is a partial skull recovered from the Barranquita Formation at Río Cañada Honda locality. Stratigraphic and sedimentological analyses of the Río Cañada Honda section identify a mud-dominated sequence with interstratified sandy-gravelly facies, reflecting a depositional environment characterized by fluvial and alluvial-eolian conditions. These deposits fill depressed erosive surfaces on the igneous-metamorphic basement of the Sierra de San Luis, known locally as “pampas de altura”. The anatomical study of the skull reveals features consistent with Toxodon platensis, including its characteristic dental morphology and a relatively flattened cranial profile. Metrical comparisons indicate a smaller size than some contemporary specimens, suggesting a subadult ontogenetic stage. Furthermore, the use of medical CT scans allows for the description of poorly known intracranial anatomy of this taxon and the discussion of previous interpretations. The resulting braincast shows oval-shaped cerebral hemispheres with clear but shallow gyrification, well-developed temporal lobes, and protruding ‘plowshare-shaped‘ olfactory lobes. The epitympanic sinus is tear-shaped and smaller than in other toxodotids. Paleobiogeographically, the occurrence of T. platensis in fluvial sediments of the Barranquita Formation serves as a critical geographic bridge within the “Arid Diagonal” in Argentina filling a regional gap between the eastern lowland records and those of the Andean region.
The term “diversity” has been used several times for the Brazilian Devonian fauna without considering its true ecological meaning, which may hinder a deeper understanding of this fauna over time. The main goal of this paper is to investigate the diversity patterns, origination and extinction rates of brachiopod throughout the Devonian in the Amazonas, Paraná, and Parnaíba basins, in order to assess how the global biotic crises impacted the fauna. The Ponta Grossa Formation (Pragian–Emsian), in Paraná Basin, exhibited the highest richness and diversity indexes, associated with moderate origination and extinction rates, reflecting a diverse and heterogeneous community. In the Amazonas Basin, the Maecuru Formation (Emsian–Eifelian) also showed peak richness and diversity, but with a high extinction rate, indicating a faunal renewal. In the Pimenteira Formation, Parnaíba Basin, high extinction rates and low origination contrast with the high origination, and no extinction records in the Cabeças Formation. Maximum diversity in the Paraná Basin occurred during the Zlíchov event interval, whereas the Amazonas and Parnaíba basins recorded high extinction rates during the same time. The Kačák event correlates with the final collapse of the endemic fauna, evidenced in the Amazonas Basin by the balanced rate of origination/extinction rates in the Barreirinha Formation and in the Paraná Basin by the post-crises community of the São Domingos Formation. The results emphasize that paleoecological trajectories were modulated by paleogeographic and local paleoenvironmental factors, as well as by the differential resilience of the Malvinoxhosan fauna, demonstrating that the Devonian biotic crises did not uniformly impact brachiopod faunas.
The Moreno Hill Formation of the Salt Lake Coal Field (New Mexico, USA) preserves terrigenous sediments deposited from ∼90.9 until after 88.6 Ma, a critical window of climatic recovery following the ∼94.5 Ma peak of the Cretaceous Thermal Maximum. Recent fieldwork uncovered new macrofloral assemblages: a lower member flora derived from a paralic delta plain, with carbonaceous, pedogenetically altered floodplain sediments indicating often waterlogged conditions, and an upper member flora uncovered from slightly drier, more distal floodplain sediments. We report 18 distinct foliar morphotypes from the study of 116 leaf specimens. Dicot angiosperms are the most diverse in both assemblages, including platanoids, Saliciphyllum, and Cinnamomoides. While only two dicot morphotypes are shared between the lower and upper assemblages, two conifers (Brachyphyllum and taxodiaceous Cupressaceae indet.) are found in both. The fossils at both sites were collected from overbank deposits and lack evidence for significant transport; thus, we infer that the floodplains adjacent to channels during this interval were occupied by a mixed angiosperm-conifer woodland ecosystem. Although the two assemblages are separated by ∼1.5 to 2 million years, they reflect similar floodplain woodlands on a changing landscape in which the Western Interior Seaway was regressing and the local conditions drying. Sedimentological, leaf physiognomic, and wood growth-ring data collectively support persistent warm, yet gradually more seasonal conditions after the thermal maximum. This first report of Moreno Hill Formation leaf macrofossils establishes a regional Turonian–Coniacian palaeobotanical baseline for future studies of vegetation and ecosystem change in the southern Western Interior.
Coleolus carbonarius Demanet in Demanet and van Straelen (1938) is reported for the first time from the Moscovian (Carboniferous) of Africa. In Algeria, this species occurs in large numbers as densely packed, preferentially oriented shell accumulations on limestone bedding surfaces, while being conspicuously absent from the overlying and underlying mudstone intervals. Despite this broad local abundance, nearly all previously documented occurrences of Coleolus are restricted to the European sector of the Palaeo-Tethys Ocean, with Algeria representing the only known African record. The Carboniferous distribution of the genus indicates a strong affinity for warm, low-latitude marine settings within the Palaeo-Tethyan realm. In the Moscovian of Algeria, Coleolus may have constituted a relatively abundant component of the benthic community, subsequently redistributed by hydrodynamic processes. Alternatively, the original populations may have been less numerous, with shell concentrations produced through winnowing, transport, and redeposition, thereby artificially enhancing their apparent ecological significance. The available evidence suggests that soft-substrate environments, including both calcareous and siliciclastic mud bottoms, represented the preferred habitat of Coleolus.
This study presents biostratigraphic and sedimentological insights from six newly documented and two legacy described outcrops from the Tinjar Province of Central Sarawak, Malaysia. Palynological analysis identified four local palynomorph assemblage zones: FT-I (late Oligocene), FT-III (Early Miocene), SP-I (Late Miocene–Pliocene) and SP-II (Late Pliocene). The Nyalau Formation contains the FT-I and FT-III zones, while strata containing SP-I and SP-II zones are part of an unnamed unit that is age-equivalent to the Liang Formation. Two unconformities were identified in the studied sections: (i) an angular unconformity separating upper Oligocene from Lower Miocene strata in the Nyalau Formation with an approximately 2 Myr age gap correlated with the Base Miocene Unconformity of the offshore Sarawak Basin; and (ii) an unconformity between the upper Oligocene Nyalau Formation and the Pliocene Liang Formation-equivalent strata; this unconformity represents a hiatus of approximately 19 Myr correlated with the offshore Base Cycle VI Unconformity and is linked to a widespread uplift event in NW Borneo during the Miocene. The sediments were deposited in the supratidal to intertidal zone of a marginal marine setting, in proximity to fluvio-deltaic sources and influenced by periodic marine transgressive events. Sedimentological records revealed four facies successions: (i) tide-dominated delta; (ii) estuarine bay; (iii) wave-dominated shoreface; and (iv) fluvio-tidal channel. Palynological data suggest a predominantly warm-wet, humid climate with intermittent seasonal conditions for the late Oligocene, Early Miocene and Late Miocene–Pliocene.
Pandanaceae (the screw-pine family) represents an early-diverging monocot lineage with a predominantly paleotropical distribution, yet its fossil record remains sparse and uneven, particularly in South Asia. Here, we report well-preserved fossil leaves attributable to Pandanites trinervis (Ettingsh.) J. Kvaček et A.B. Herman, from the late Oligocene Tikak Parbat Formation of the Makum Coalfield, Assam, India. The fossils are characterized by elongate linear laminae having a distinctive M-shaped transverse section with midvein (1°), uniformly developed 2° parallel veins of the same width, transverse veins (3°) obliquely to perpendicularly oriented, and well-developed marginal prickles, a combination of characters diagnostic of Pandanaceae. This record constitutes macrofossil evidence of pandanaceous leaves from the Indian Paleogene and bridges a critical temporal and geographic gap between Late Cretaceous Laurasian occurrences and younger Cenozoic tropical records of the family. The Makum fossils suggest Paleogene persistence and ecological continuity of Pandanaceae across the paleotropics prior to their Neogene diversification and temporally coinciding with molecularly inferred diversification of extant Pandanus lineages in the late Eocene–Oligocene. Sedimentological, palynological, and CLAMP-based paleoclimatic data indicate deposition in warm, humid, lowland deltaic environments dominated by freshwater swamps, riparian corridors, and evergreen forests, closely matching the ecological preferences of extant Pandanaceae. These findings underpin the role of the Indian subcontinent as an important region of persistence for pandanaceous lineages during the Paleogene and provide new insights into the biogeographic history of the family in tropical Asia.
Extinct sloths constituted a significant component of the faunal assemblage inhabiting the South American continent during the Pleistocene, with extensively distributed fossil records across the continent. The Scelidotheriid Catonyx cuvieri is commonly found in tanks and caves in Brazil. Paleoecological (chronology, diet, habitat) and paleopathological (articular and vertebral lesions) studies of extinct sloths have expanded, providing insights into previously undescribed features. We describe a spondylosis deformans (non-inflammatory condition characterized by the development of bony projections) in the sacral vertebra of Catonyx cuvieri, recovered from a cave in Bahia, based on macroscopic anatomical characteristics. The observed lesion indicated a grade 2 enthesophyte resulting from abnormal bone formation in the vertebral body related to aging. (c) 2026 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Spirodela Schleid. is one of the most abundant and widespread giant duckweeds (Araceae: Lemnoideae), although its fossil record remains relatively unexplored. We present a well-preserved, impressed and compressed fossil rosette bearing four leaves similar to this extant free-floating great duckweed from the early Eocene (Palana Formation) sedimentary sequences of Gurha Lignite Mine, Rajasthan, western India. We infer its taxonomic position based on phylogenetic analysis using macromorphological traits and compare it with other modern and fossil species of Lemnoideae. The fossil specimen is characterized by four peltate sessile leaves (one mother, two daughters, and one granddaughter) arranged spirally in a rosette, leaves with campylodromous venation, and the presence of stolons and adventitious roots. After a thorough comparison, we described our Eocene specimen as a new genus and species, namely Eospirodela indica Ali, Almeida et Khan gen. et sp. nov. Together with other fossils reviewed from the literature, this new taxon helps to elucidate the evolution of duckweeds. Our finding strongly supports the existence of a freshwater ecosystem complementing the earlier published data on the Rajasthan Basin during the early Eocene (55 +/- 10 Ma), in contrast to the present desert vegetation of the region. It also throws light on the paleoecological and paleobiogeographical history of duckweeds. (c) 2026 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
The Early Ordovician saw a transition in reef type from microbial-dominated buildups to gradually increasing skeletal frameworks, expressed as regionally heterogeneous constructional pathways. Among these early reef builders, Pulchrilamina Toomey and Ham (1967) has long been regarded as a problematic laminar reef-builder of uncertain affinity. The genus was initially reported from Laurentia and has subsequently been recognized elsewhere only from South China. Here, we re-examine the type material of Pulchrilamina. The skeleton is composed of stacked laminar sheets alternating with sediment, internally composed of long, slender, spinose rod-like elements that are variably spaced, locally inclined, and protrude both downwards beneath the basal growth surface and upwards beyond the uppermost lamina into overlying sediment. These elements are weakly integrated with locally preserved cyst plate-like fabrics. Their morphology and mode of development differ from the pillar architectures that are characteristic of labechiid stromatoporoids, supporting the interpretation of the structures as spicular elements rather than as pillars of stromatoporoid-grade skeletal elements. Together, these features indicate that Pulchrilamina may record an intermediate skeletal grade between constructional organizations dominated by cyst plates and skeletal architectures characterized by spicular elements, and requires further examination using better-preserved material and additional valid taxa attributed to pulchrilaminids. The emergence of Pulchrilamina broadly coincided with the appearance of calcified reef-associated organisms, including stromatoporoids and bryozoans. These patterns support the interpretation that early skeletal reef ecosystems developed through multiple, regionally restricted constructional pathways that reflect an early phase of experimentation in hypercalcified skeletal construction among sponges. (c) 2026 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Molluscs are important components in both past and modern ecosystems. Understanding their evolutionary history relies on accurately interpreting their past morphologies as preserved in the fossil record. However, organisms typically undergo decay before geological processes intervene to stabilise parts of their anatomy as fossils. To assess the impact of decay on our understanding of ancient morphologies, decay experiments have been conducted in controlled laboratory settings. Such experiments have rarely been applied to gastropods, as their mineralised shell covers internal organs, making direct observation of decaying anatomies experimentally challenging. Here, we conducted decay experiments on 55 snails over 10 days, using histological sections to observe internal morphological changes over time. Our results show that most of the organs we monitored decay uniformly, except for the hepatopancreas, which decomposes more slowly than the rest. Importantly, decay proceeded faster on the outside than on the inside of the hepatopancreas, suggesting that digestive enzymes of microbiota in gastropods may not be as efficient at tissue degradation as those in the digestive systems of other bilaterians. (c) 2026 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
The Upper Mississippian (Middle Chesterian) Fayetteville Shale has long yielded exceptionally preserved plant and invertebrate fossils, but its vertebrate fossils have only recently been investigated in earnest. These investigations have yielded numerous three-dimensionally preserved chondrichthyan remains, capturing key features for reconstructing early chondrichthyan relationships. Over the last several decades, paleobotanists and invertebrate paleontologists have collected vast numbers of phosphatic concretions from this formation. For this investigation, dozens of these concretions housed at the American Museum of Natural History were split open or lCT-scanned, revealing a diversity of vertebrate fossils previously unknown from these deposits. We provide an account of the vertebrate diversity, as well as a summary overview of previous hypotheses of Fayetteville Shale paleoecology and depositional environment. Synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping, combined with powder diffraction, were used to characterize the elemental and mineralogical composition of a concretion and its fossil content. The obtained data support reconstructions of the depositional environment and explain the exceptional preservation of calcified cartilage but limited preservation of bone and shell. (c) 2025 The Authors. Published by Elsevier Masson SAS. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).
The Frasnian-Famennian (F-F) boundary mass extinction, associated with the Kellwasser events, triggered one of the most severe biodiversity crises of the Phanerozoic. The Plan di Zermula D (PZD) section in the Carnic Alps of northeastern Italy provides the first record of a deposition of black shale level at the boundary in this region. The rich conodont association allows to identify seven conodont zones from FZ 13b to the Palmatolepis crepida Zone, yielding a high resolution biostratigraphic framework for the F-F interval. Conodont diversity dropped abruptly by about 80% at the boundary, with only a few taxa surviving. Post-crisis recovery was delayed and gradual, with diversity remaining low in the earliest Famennian and rising significantly in the Palmatolepis crepida Zone. Comparison with nearby sections lacking the black shale layer at the boundary confirms the peculiar depositional conditions in the Carnic Alps, which could explain the slow recovery in the PZD section compared to other areas. (c) 2025 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
The Oligocene-Miocene sediments of the North Alpine Foreland Basin (NAFB) provide a valuable continental archive for reconstructing paleoenvironmental change and exploring potential links to global climate cycles. This study focuses on middle Burdigalian deposits of the Upper Marine Molasse, specifically the widespread Neuhofen Formation (NH Fm.) at the Mitterdorf claypit (SE Germany), a key site for understanding regional environmental dynamics. We investigate paleoenvironmental shifts and the origin and timing of previously unexplored channel structures in the upper NH Fm. through detailed analysis of benthic and planktonic foraminiferal assemblages, along with oxygen and carbon stable isotope data. Eighteen samples were collected from two parallel vertical sections: one encompassing the sediment adjacent to a channel structure, and the other located within and beneath the sediment of the channel structure. Our results document a gradual shallowing of depositional environments from middle neritic (similar to 30-100 m) to inner neritic (similar to 0-30 m) conditions, under mostly warm surface-water temperatures of 23-24 degrees C. Episodic freshwater influx, indicated by isotopic signatures and characteristic foraminiferal taxa, led to water-column stratification and elevated nutrient levels. Toward the top of the section, reduced isotopic offsets between benthic and planktonic foraminifera indicate weakened stratification in response to continued shallowing and potentially drier climatic conditions. The channel structures are interpreted as erosional unconformities, possibly formed by subtidal currents in a shallow marine setting. Integrating magnetostratigraphic age constraints from previous studies, our data support the interpretation that the global 405 kyr orbital eccentricity cycle around 17.67 Ma is recorded in the upper NH Fm., influencing regional climate conditions in the NAFB during the middle Burdigalian. (c) 2025 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Layang Mawas Cave represents the first numerically-dated Middle to Late Pleistocene fossil site in the eastern part of Peninsular Malaysia. Previous research mostly focused on the Quaternary fossil sites located in the western part of the peninsula that is distinctly separated from the east by the granitic Main Range batholith. A survey of the fossil-bearing breccia in Layang Mawas Cave yielded 21 remains, mostly tooth fragments and isolated teeth, from at least eight taxa. Stratigraphic and sedimentological evidence suggest that all the fossils found in different areas of the cave relate to the same breccia formation event. The faunal assemblage is comparable with those from five other Middle and Late Pleistocene West Malaysian sites. It also includes a new biogeographic record for Pleistocene orangutan and the first directly-dated occurrence of a Proboscidea in the region. The polymictic nature of both allochthonous and autochthonous clasts with large grain size difference in the breccia indicates an intense mixing of fauna through successive episodes of deposition and post-depositional erosion. Our study suggest that the fossils were deposited as part of natural sedimentary processes over along history of hydraulic or gravitational transportation and reworking, possibly after being accumulated by rodents. Direct dating of a few selected teeth from the fossil assemblage using U-series and ESR methods was quite challenging given the existing uncertainty around the dose rate evaluation. Despite some apparent scatter possibly partly resulting from this intrinsic uncertainty, our results nevertheless return a Late Pleistocene (MIS 5 to 4) age for most of the fossil teeth, while a last tooth coming from another area within the chamber most likely shows an older Middle Pleistocene age (MIS 7 or older). Although all dated specimens may be in first instance related to the same breccia formation event, we cannot reasonably exclude that some of them may have been reworked from significantly older deposits or correspond to various phases of fossil accumulation. (c) 2025 Published by Elsevier Masson SAS.
The present investigation integrates Fourier transform infrared (FTIR) spectral features with Gas Chromatography-Mass Spectrometry (GC-MS) data to explore the botanical origin of Miocene ambers from northeast India, and to assess their polymerization extent. The FTIR spectra of these ambers exhibit strong similarities to those of modern Dipterocarpaceae resins, indicating a likely origin from the Miocene Dipterocarpaceae family. The presence of a distinct triplet band at approximately 1384, 1378, and 1369 cm(-1) further supports this botanical linkage. This study presents a novel evidence of p-cymene (m/z 119, molecular weight 134), a volatile monoterpenoid embalmed in Miocene ambers from northeast India. Besides, these ambers comprise C-15 bio-sesquiterpenoids (beta-bourbonene, beta-elemene, beta-cadinene, beta-cubebene, alpha-humulene, and germacrene D, among others), geo-sesquiterpenoids (calamenene (cadina-1,3,5-triene), dihydro-ar-curcumene, cadina-1(10),6,8-triene, and cadalene), C-30 pentacyclic triterpenoids (oleana-2,13(18)-diene, oleana-2,12-diene, oleana-2,18-diene, ursa-2,12-diene, A-neo-oleana-3(5),12-diene, and A-neo-ursa-3(5),12-diene), along with beta-amyrone and alpha-amyrone, the oxidative derivatives of beta-amyrin and alpha-amyrin, respectively. The co-occurrence of C-15 sesquiterpenoids and pentacyclic triterpenoids having oleanane and ursane skeletons suggests that the ambers represent Class II (dammar-type) resins, likely secreted by the abundant Dipterocarpaceae vegetation under the warm, humid conditions of the Miocene in northeast India. Furthermore, relatively higher abundance of geoterpenoids over these C-15 bioterpenoids, the presence of oxidized amyrins, lower 1700/1460 values (<0.60), and a higher 1384/1243 FTIR spectral ratio (>3.00) than those of the modern Dipterocarpaceae resins, suggest mild polymerization of these Miocene resins during fossilization. (c) 2025 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
The red deer (Cervus elaphus) is among the most common species in Italian faunal assemblages from the Middle and Late Pleistocene. However, palaeontological deposits yielding numerous and well-preserved remains that allow for accurate morphological and biometrical analyses of this mammal are extremely rare. The abundant remains of C. elaphus from the recent investigation of Grotta Guattari, a cave well known for numerous Homo neanderthalensis remains, provide the opportunity to examine the characteristics of the red deer in the Italian peninsula during the MIS 4, a paleoenviromentaly particularly dynamic period. This study allows us to confirm some biochronological considerations on this species and to infer some paleoecological features of the site. (c) 2025 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
