The name Andinotoxodon bolivarensis was originally proposed in an unpublished doctoral dissertation, rendering it nomenclaturally unavailable under the International Code of Zoological Nomenclature (ICZN). Despite this, the name has been consistently used in the scientific literature for over three decades, appearing in numerous studies on Neogene Toxodontidae. Here we make the name Andinotoxodon bolivarensis available for the first time, in compliance with Articles 8.1, 16.4, and 72.3 of the ICZN. We designate as holotype MNHN-Bol-V 3570, a nearly complete cranium with associated mandible, postcranial elements, and partial manus, from the Honda Group (Quebrada Honda, Tarija, Estado Plurinacional de Bolivia), dated to approximately 13.1-12.7 Ma. A new diagnosis is provided, distinguishing Andinotoxodon bolivarensis from all other toxodontid genera based on upper molar and mandibular morphology. Referred material from the late Middle to Late Miocene of Ecuador and Bolivia is also documented. The publication of this work satisfies the criteria of Article 23.2 of the ICZN by promoting nomenclatural stability of a name long-recognized by the paleontological community.
Adelphailurus kansensis is a puma-sized felid, originally described from fragmentary material in the Edson Quarry (Kansas, Mio-Pliocene). Here, we describe a nearly complete cranium from the Wikieup local fauna of the Big Sandy Formation, along with associated dental remains, and refer it to A. kansensis. Comparative analysis with Metailurus major, Yoshi minor, Y. garevskii, and Y. yongdengensis reveals a unique combination of features. A. kansensis shares certain traits with Metailurus (narrow snout, M1 orientation) and Yoshi (rounded cranial profile) but differs from both in having thinner zygomatic arches of nearly constant width, a more pronounced postglenoid process, and specific dental characteristics, including a P3 lacking an anterior accessory cusp and upper canines with serrations on both margins. Geometric morphometric analyses place A. kansensis morphologically between Metailurus and Yoshi, illustrating its intermediate cranial proportions yet confirming its distinctiveness. Several elements, including this cranium and previously misattributed specimens, were originally referred to Pseudaelurus, highlighting the persistent taxonomic issues surrounding early diverging felids. This study refines the diagnosis of A. kansensis, and clarifies its relationships within "metailurins."
We report the first fossil occurrence of Masturus from the Middle Miocene Hagjeon Formation of the Pohang Basin, southeastern Korea. It is referable to Masturus cf. lanceolatus based on a distinctive combination of features, including a fused upper beak formed by premaxilla, eight caudal vertebrae, a clavus bearing posteriorly positioned middle fin rays, a clavus margin with a median projection, absence of ossicles on paraxial clavus fin rays, and a dome-shaped epioccipital that is only moderately prolonged posterodorsally. The specimen is a nearly complete skeleton preserved in lateral view within dark gray mudstone and retains soft tissue impressions interpreted as dermal scale imprints. The dorsal and anal fin ray counts (20 and 17) fall within the range of extant Masturus lanceolatus. The fossil is extremely small, with a total length of about 9 cm, and the inferred posterior prolongation of the middle fin is most consistent with a juvenile individual, potentially corresponding to an early ontogenetic stage in extant Masturus. Because juvenile comparative skeletal data are limited and the temporal separation from the extant species is substantial, a confident species-level assignment is not possible. This discovery demonstrates that the molecular phylogenetic analysis (7.2-18.9 Ma) is corroborated by the paleontological record, provides the first calibration point for Masturus evolution, and enriches our understanding of Miocene pelagic ecosystems on the Korean Peninsula.
The family Proterotheriidae has ancient antecedents in Uruguay, even though the accurate documentation about its diversity and distribution has only recently been organized. Currently, the record of Proterotheriidae in Uruguay has been expanded and increased, encompassing five lithostratigraphic units of various ages, ranging from late Oligocene to Early Holocene. In this work, a new genus and species, Oligopterna orientalis, is reported. This new taxon is the oldest and only late Oligocene record of the family from Uruguay, recovered from the Fray Bentos Formation. The specimen FC-DPV 2811 consists of a right mandibular fragment preserving the alveoli of dp3, enamel of the posterior lobe of dp4, and m1 erupting. The diagnostic characters of the new taxon present in the m1 are: talonid shorter than the trigonid; slim dental cusps and lophids; metaflexid deeper than the entoflexid; a conspicuous conical paraconid located mesially to the metaconid; paraconid, metaconid, and hypoconulid aligned lingually, almost at the same plane, and entoconid strongly lingually located-in front of hypoconulid in the same coronal plane-positioned out of paraconid-hypoconulid plane. This study incorporates imaging techniques and contributes to increasing the diversity of the family in the late Oligocene (Deseadan age).
Hyaenids are an integral part of the Neogene and Quaternary ecosystems of the Old World, including some of their most specialized apex predators. However, the exact evolutionary drivers that led to the taxonomic and adaptive radiation of the hyenas are still unclear. Intraspecific aggression over territory or for social hierarchy is a common behavior in the extant members of the family, affecting many aspects of their ecological role. Here we describe a bite puncture on a skull of Adcrocuta eximia from the middle Turolian (Late Miocene) locality of Torrentet dels Traginers (Vall & egrave;s-Pened & egrave;s, Spain), and another one on a skull of Chasmaporthetes lunensis from the Early Pleistocene locality of La Puebla de Valverde (Teruel, Spain). The Adcrocuta puncture is located above the orbits, whereas the Chasmaporthetes one is located anterodorsally to the left orbit. Examination of external morphology and computed tomography (CT) slices reveals evidence of healing in both skulls. Based on the size and morphology of the punctures, they were probably caused by another hyena, most possibly another individual of the same species. In Chasmaporthetes, attributing the agent to Pliocrocuta or, less possibly, to an ursid or a felid is not excluded. Similar injuries are observed in specimens of extant species, including the brown and spotted hyena, showing that such trauma can occur in both social and solitary species. These specimens show that intraspecific aggression was probably present in fossil hyenas, further strengthening the resemblance between fossil and modern hyenas and providing additional information on the paleobiology of bone-crushing hyaenids.
The Chinese crocodile lizard (Anguimorpha, Pan-Shinisaurus Shinisaurus crocodilurus) is an endangered species inhabiting the lowland rainforests of southeastern China and northern Vietnam. The evolutionary history of this clade remains poorly understood, as only five fossil species and a few fossil specimens are described from the Lower Cretaceous of China and the Cenozoic of Europe and North America, revealing a considerable gap in the fossil record. A new anguimorph, Acutodon villeveyracensis gen. et sp. nov., is described from the lower Campanian (Upper Cretaceous) locality of Villeveyrac (H & eacute;rault, France), corresponding to a freshwater subtropical paleoenvironment. The species is attributed to a pan-shinisaur anguimorph based on a toothed maxilla sharing multiple characters with the extant Sh. crocodilurus and its fossil relatives, notably tall, tapered, and recurved teeth, with mesiodistally constricted tooth bases lacking basal infoldings but possessing medial resorption pits, and a posteromedially shifted anterior superior alveolar foramen. This Cretaceous record is the oldest in Europe for pan-shinisaur lizards. It pre-dates the occurrence of this clade in Europe by around 30 Myr, raising questions about the paleobiogeographic history of pan-shinisaur lizards.
Antiskarn refers to skarn-like assemblages formed by reactions between carbonatite melts and silicate wall rocks and provides critical insights into carbonatite petrogenesis and related mineralization. Here we report calc-silicate assemblages associated with Triassic (229-206 Ma) carbonatite dikes at Huayangchuan, Qinling orogen, central China. Two texturally distinct andradite-rich garnets are distinguished. Fine-grained euhedral garnets yield a U-Pb age (213 +/- 5 Ma) coeval with carbonatite emplacement and represent syn-magmatic "antiskarn" reactions between carbonatite melt and silicate wall rocks. Euhedral garnets intergrown with sulfides yield a U-Pb age of 130.0 +/- 5.2 Ma, identical to nearby granite (132 +/- 1 Ma), and possibly represent a later skarn reaction between granite-derived fluids with solidified carbonatite rocks. Mineral paragenesis in the Triassic assemblages defines three successive stages, reflecting the melt and fluid evolution during carbonatite solidification. These results demonstrate that direct geochronology is essential for distinguishing syn-magmatic antiskarnisation from later hydrothermal modification in carbonatite-related systems.
High-resolution seafloor data from the Gulf of Corinth, Greece, reveal new insights into rift-margin submarine fans deposited at the base of fault scarps. The steep (13 degrees) Sythas canyon cuts into the submarine Lykoporia fault and is carpeted by low-relief, elongate rhomboidal bed forms. Across the fault, the canyon passes abruptly into the 6-km-radius Sythas submarine fan. The proximal fan (similar to 3 degrees gradient) contains multiple discontinuous channels, erosional cyclic steps, and scour fields. Channels shallow and broaden onto the medial fan (similar to 1 degrees gradient), which is characterized by trains of depositional cyclic steps that pass into low-relief lobes on the distal fan (similar to 0.18 degrees gradient). These morphological relationships compare to the submarine slopes of fan deltas and submarine fans in fjords but contrast markedly with established channel-levee distributary models of submarine fans. Sediment gravity flows were likely stratified, with a thin, concentrated, coarse-grained, and supercritical basal layer. Smooth interchannel areas suggest the basal layer (<5 m thick) was contained within erosional relief, before dissipating rapidly within similar to 3 km of the canyon mouth, with flows transformed into dilute, subcritical turbidity currents on the distal fan. This is the first time a continuum of proximal to distal bed forms has been documented on an active base-of-fault-scarp submarine fan and linked to sediment-gravity-flow structure and transitions from supercritical through transcritical to subcritical conditions.
"Palaeornis" cliftii is among the earliest British pterosaur discoveries. Although considered a dubious taxon by most recent authors, the type and only specimen is presently recognized as an azhdarchoid humerus, potentially closely related to Tapejaridae. Reassessment of "P." cliftii demonstrates a unique morphology among azhdarchoid humeri, and therefore it is provisionally accepted as a valid species. As the genus name Palaeornis Mantell, 1844 is preoccupied by Palaeornis Vigors, 1825, we offer Rexarthuria, nom. nov. as a replacement name. Rexarthuria cliftii, comb. nov. represents the oldest azhdarchoid material presently known from Europe.
Recent experimental work has demonstrated that tourmaline (tur) can serve as a relatively high-temperature (400-600 degrees C) 40Ar/39Ar geochronometer. Incremental heating of tur from two mineralized localities in the Yukon (Canada), the Casino Cu-Au-Mo porphyry (74.8 +/- 0.74 Ma) and Seagull Batholith (96.9 +/- 0.14 Ma), yield 40Ar/39Ar plateau ages that overlap with zircon U-Pb ages from the host plutons, indicating rapid development of hydro-thermal mineralization following regional magmatism. However, differences in K contents between Casino and Seagull tur and differing crystallization textures between successful (age plateaus) and unsuccessful (discordant) heating experiments illustrate that crystallochemical features (e.g., partial replacement) exert a strong control on geochronology. A petrochronologic approach integrating tur texture, chemistry, and 40Ar/39Ar ages can contribute insights into the formation conditions of tur-bearing mineralized systems.
