A new species of dissorophoid temnospondyl, Melanerpeton kuselense new species, is reported from the Remigiusberg Formation (Carboniferous-Permian boundary) of southwestern Germany. The type and only known specimen is a skull belonging to a moderately advanced larva with distinctive features: (1) a very slender postorbital skull table, (2) large nasal, (3) short squamosal giving a short gape, and (4) a gracile and extremely small pterygoid. Phylogenetic analysis finds it to fall well within the branchiosaurids, above the Pennsylvanian Branchiosaurinae, and sister taxon to Melanerpeton pusillum Fritsch, 1878 from lower Permian deposits of the Czech Republic. It is not closely related to any of the branchiosaurids from the Saar-Nahe Basin, adding to the distinctive Remigiusberg tetrapod faunal assemblage.

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This study describes the Serkinskaya faunal complex of the Siberian lower Cambrian Kessyusa Group, which includes a fragment of gnathobase, several scalids of priapulid-like organisms, various morphotypes of spines, organic films with outgrowths, and other organic remains. Organic microfossils that we identified as gnathobase fragments (a jaw-like fragment and a robust spine with porous structure) were studied via Raman spectroscopy, and phase distribution maps were constructed to identify different kerogens. The jaw-like fragment has heterogeneity on the surface of the microfossil and can be interpreted as reflecting differential preservation of two different layers of the cuticle. The age of these remains is estimated to be Cambrian Fortunian to Stage 2 (Vendian–Cambrian, possibly Tommotian), which makes the identification of gnathobase fragments one of the oldest known occurrences of evidence for durophagy. These findings confirm the presence of filter-feeding, deposit-feeding (priapulids), vertical mixing of the sediment in the first centimeter, predation pressure (cuticle with outgrowths), and possible durophagy in the earliest Cambrian.

This study considers Glomalveolina subtilis Hottinger, 1960, to be a distinct species within the genus Glomalveolina, previously grouped with G. lepidula (Schwager, 1883). This species is distinguished by unique morphological and biometrical features, setting it apart from closely related species and establishing it as a significant biostratigraphic marker for the early Ypresian (SBZ6-7) in the central Neo-Tethys. Although first reported from the Iranian platform, it expands the paleobiogeographic distribution of G. subtilis, with earlier records from the western Neo-Tethys (Mediterranean and North African basins) during the early Ilerdian (SBZ5–SBZ6) and from the eastern Neo-Tethys (China) in the middle Ilerdian (SBZ7–SBZ8). The Alveolina biostratigraphy is correlated with the calcareous nannofossil biostratigraphy, placing it in the middle part of the NP10 Zone. This discovery highlights the broader distribution of G. subtilis and its significance in refining biostratigraphic correlations and understanding foraminiferal evolution during the Paleocene–Eocene transition.

The rhynchonellide brachiopod Altaethyrella Severgina, 1978 is a key component of the shallow-water Altaethyrella brachiopod fauna that flourished in the tropical Proto-Tethys during the Katian (Late Ordovician). This study describes an unusually small species of the genus, Altaethyrella xuejiaoi new species, from the lower Katian (Ka-1) Yingan Formation in northwestern Tarim, Xinjiang, Northwest China. With an average length of 8.60 mm, width of 9.73 mm, and depth of 5.69 mm, it is approximately two-fifths the size of typical Altaethyrella species, although the presence of a central myophragm in the dorsal cavity and well-developed teeth confirms that the specimens of the new species are mature and not simply juvenile forms. This species inhabited the shallow-water reef-stromatoporoid bioherm, providing new insights into the origination and early evolution of the rhynchonellides. Furthermore, this study contributes new generic occurrence data that will improve our understanding of the paleogeographic distribution of the Altaethyrella fauna prior to the Late Ordovician Mass Extinction (LOME).

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Upper Middle Devonian to lowermost Upper Devonian brachiopods from Mount Józefka near Górno (Holy Cross Mountains, Poland) are described from the Laskowa Góra Beds (mostly top-Givetian dengleri Conodont Biozone) and Szydłówek Beds (Givetian–Frasnian transition). Twenty species are present, whereof two new ones. Glosshypothyridina theophili new species is larger and has a less angular hinge margin than G. procuboides (Kayser, 1871). Data on internal features of Hypothyridina Buckman, 1906, Glosshypothyridina Rzhonsnitskaya, 1978, and Tullhypothyridina Sartenaer, 2003 are summarized on the basis of published and unpublished sources, allowing rectification of previous incorrect interpretations of these genera. Kyrtatrypa stanislai new species resembles middle Givetian K. pauli Halamski and Baliński in Halamski et al., 2024, but possesses rudimentary dental nuclei. Similar (previously unnoticed) minute dental nuclei occur in the type species K. culminigera (Struve, 1966), so the diagnosis of Kyrtatrypa Struve, 1966 is emended. The moderately diverse fauna thrived in biogenic and muddy niches within and around perireefal coral thickets in the protected ramp-slope of the northern Kielce carbonate platform. The at-most modest replacement of brachiopod faunas between the middle Givetian and the early Frasnian times during the post-Taghanic ecosystem recovery is confirmed for the Euramerican shelf. However, a different response to global stresses is evident for the sessile benthos across the Middle–Upper Devonian boundary in the intrashelf basin and the stromatoporoid-coral bank settings. Off-reef communities were more resilient, affected by extinction probably half as much as the more sensitive reef-related faunas. The ecological-evolutionary stasis among bottom-level shelly benthos contrasts with the extinction of the Hamilton/upper Tully fauna in the Appalachian Basin, the type area of the Taghanic Crisis.

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Angustothyrididae Dagys, 1972 is a key group of terebratulide brachiopods, because it exhibits characteristics bridging the two major suborders, Terebratulidina and Terebratellidina, and could represent an evolutionary link between them. However, the taxonomy of its type genus, Angustothyris Dagys, 1972, has remained poorly understood. Our restudy of specimens from the Middle Triassic of Hungary and southwestern China, including material from the type localities, reveals that the specimens previously assigned to Angustothyris actually represent multiple genera. This indicates that the diversity of this group has been underestimated, leading us to establish Balatonithyris new genus, Qianothyris new genus, and Angustothyris aszofoensis new species. The long teloform loop in Qianothyris n. gen. fills a morphological gap between short-looped terebratulidines and long-looped terebratellidines, supporting a Late Permian–Triassic origin of the terebratellidines from the Angustothyrididae. The morphological evidence, however, conflicts with molecular data that suggest an earlier divergence between the two suborders. This contradiction implies that either the Angustothyrididae is not the direct ancestor of terebratellidines, or that the terebratellidines are a polyphyletic group with multiple evolutionary origins.

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A suite of Miaolingian to Furongian (i.e., traditional middle-upper Cambrian) trilobites are reported from the Abrigo Formation at exposures along Nugget Canyon and adjacent Peppersauce Canyon, Santa Catalina Mountains, Arizona, USA. These fossils are uncommon in the region because the unit predominantly comprises coarser-grained siliciclastic facies deposited near shoreface settings where fossils are not often preserved. Trilobites include Agnostidae gen. indet. sp. indet. and the ptychoparioids Ehmaniella sp. indet.; Neoblairella sp. indet.; Altiocculus sp. indet.; Arapahoia ransomei (Stoyanow, 1936); Bolaspidella sp. indet.; Bolaspididae gen. indet. sp. indet.; Brachyaspidion sp. indet.; Cedaria sp. indet.; Crepicephalus sp. indet.; Elburgia sp. indet.; Eldoradia linnarssoni (Walcott, 1884); Eldoradia prospectensis (Walcott, 1884); Iddingsia sp. indet.; Modocia centralis (Whitfield, 1877); Modocia cf. M. crassimarginata Rasetti, 1965b; Modocia oweni? (Meek and Hayden, 1861); Strigambitus cf. S. transversus Palmer, 1965; and Tricrepicephalus texanus (Shumard, 1861). The type specimens of Arapahoia ransomei and Arapahoia butleri (Stoyanow, 1936) are refigured and considered synonymous. This fauna spans the Ehmaniella to Crepicephalus biozones and the Dunderbergia Biozone; the last has not been previously reported from the Abrigo Formation. This biostratigraphy is calibrated by correlation with regional strata constrained by detrital zircon U-Pb geochronology, which provides ages that are consistent with the observed biozones. Considered together, these data help correlate the Abrigo Formation to more fossiliferous and offshore successions elsewhere in Arizona, Sonora, New Mexico, Texas, USA, and beyond.

Trilobites, iconic ancient arthropods that endured throughout the Paleozoic Era, are represented by a great number of fossils and a high species richness. However, only a very small number of taxa have their soft tissues preserved, which means that the morphology and ecology of most trilobites have not been specifically determined, even though the morphology of their exoskeletons is well studied. Fortunately, modern technologies (e.g., Micro-CT and μ-XRF) provide non-destructive methods to unveil the soft tissues of fossils that might be buried in rocks. Here we use Micro-CT and μ-XRF to make a detailed study on exceptionally preserved specimens of Palaeolenus douvillei Mansuy, 1912 from the Guanshan Biota. The uniramous antennae, four pairs of post-antennal cephalic appendages, 13–15 thoracic appendages, and at least two pygidial appendages underneath the dorsal shield were revealed for the first time. In addition, we observed that the hypostome and labrum were differentiated in P. douvillei, and this species possesses both typical trilobite digestive systems—namely the crop and digestive glands—simultaneously within a single individual. From the combined evidence of morphological features and phylogenetic analysis, it is reasonable to place P. douvillei within the family Palaeolenidae, thereby contributing new perspectives to the understanding of broader trilobite evolution.

New paracrinoid echinoderm specimens are described from the Late Ordovician, Neuville Formation of Québec, Canada. These new specimens share key features with the unusually preserved and poorly known Amygdalocystites? gorgo. Based on the new specimens, this taxon is distinctive from Amygdalocystites and requires establishing a new genus. Quebecocystites gorgo new genus new combination, is exceptionally preserved, displaying fine details of the feeding structures, stalk, and holdfast, which are rarely preserved within paracrinoids. This new taxon has a combination of characteristics including an amygdaloidal body with two long ambulacra, a theca composed of numerous, unorganized, and unornamented plates lacking respiratory structures, thin and reduced floor plates, and long thin brachioles. The inclusion of this new taxon into a previously published phylogenetic analysis indicates a close relationship with the Platycystitidae and suggests that respiratory structures evolved independently four times within paracrinoids. Finally, the exceptional preservation of Q. gorgo new combination provides new insights into the paleoecology of paracrinoids including direct comparisons with other suspension-feeding echinoderms allowing for the assessment of potential competition, regeneration of brachioles, and galls and pits suggesting parasitism.

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Conodonts with conical elements that closely resemble Paleozoic species reappeared in the Early Triassic. The phylogeny, evolution, and paleoecology of these conodonts are poorly known. In this study, we describe a new species of Neostrachanognathus, N. koikei n. sp., one of the conical conodonts, and reconstruct the conodont apparatus of this species according to natural assemblages from the “Toishi-type” siliceous claystone of Japan. The apparatus of N. koikei consists of 15 elements, including two pairs of P, one pair of M, and four pairs of S elements, and a single S0 element. Notable features include conical P1 and P2 elements and nine S elements that are similar in morphology to each other. The S elements of N. koikei are identified as belonging to the form species “Neohindeodella aequiramosa” Kozur and Mostler, 1970, specifically to the morphology occurring from the Spathian to the Anisian. Furthermore, S elements of the type species of Neostrachanognathus, N. tahoensis Koike, 1998, appear to correspond to “Neohindeodella benderi” (Kozur and Mostler, 1970). Therefore, from these S-element morphologies, we conclude that Neostrachanognathus belongs to the family Ellisoniidae. These conodonts with simplified elements flourished and were widely distributed throughout the world, from continental shelves to the open ocean, during the Early Triassic to the early Middle Triassic.

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The species of Pavo and Afropavo are known as peafowl, and they occupy a disjunct distribution in southern Asia and central Africa. This distinct geographic distribution has led to debate regarding the origin and evolution of this clade, and the current fossil record of peafowl extends into the Neogene of Europe, Asia, and Africa, pointing to a more recent origin of the disjunction. Here we describe an associated partial skeleton from late Miocene deposits in the Linxia Basin, China, at the edge of the Tibetan Plateau, representing a new extinct bird taxon, Eopavo hezhengensis n. gen. n. sp. The holotype is represented by parts of the limbs, synsacrum, pelvis, pectoral girdle, and vertebrae. Morphological comparisons and a phylogenetic analysis place this extinct species as the closest relative of Pavo and Afropavo, nested within the clade Pavonini. Eopavo hezhengensis has a relatively longer spur given its smaller body frame, likely indicating that the holotype specimen derives from a male individual and that this species possibly participated in aggressive, physical contact between conspecific males as some relatives do today. The small body size of Eopavo may be linked to its occupation of a high-elevation Miocene savanna habitat, which is different from the humid forest preferred by its extant relatives. Along with older fossil peafowl records in the Himalayan area dated to 13.6 Ma, Eopavo hezhengensis helps to document the diversity and ancient history of the peafowl clade in Asia, and it indicates that peafowl dispersed from Asia to other continents during the late Miocene and Pliocene, with the Tibetan Plateau as a potential center of origin.

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Three new species of small (~25–200 g) tribosphenic marsupials, including a new genus, are described from the Early Miocene deposits of the Riversleigh World Heritage Area. Phantasmodon travouilloni, Phantasmodon minuferox, and Keeunidae gen. and sp. indet. share dental apomorphies with the late Oligocene marsupials Keeuna woodburnei and Ankotarinja tirarensis (currently Australidelphia incertae sedis), and with Australia’s oldest and most plesiomorphic marsupial, the early Eocene Djarthia murgonensis. Parsimony analyses recover these taxa as a distinct clade, warranting recognition of a new marsupial order, Keeunamorphia. In contrast, Bayesian analyses do not support the inclusion of D. murgonensis in this group, instead placing it as a stem australidelphian or stem marsupial. When early Eocene South American and European metatherians are excluded, Keeunamorphia new order appears to be the most basal (parsimony analysis) or one of the most basal (Bayesian analysis) lineages of Australidelphia. However, when these taxa are included in parsimony analysis, Keeunamorphia weakly links to South American sternbergiids and European herpetotheriids, whereas Bayesian analysis suggests keeunamorphians (excluding D. murgonensis) are more closely related to dasyuromorphians than to peramelemorphians, microbiotherians, D. murgonensis, and non-australidelphian metatherians. Keeunamorphia n. ord. may represent some of Australia’s earliest marsupials, with possible origins in Gondwana and a record spanning more than 35 million years before its apparent extinction in the Middle Miocene.

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The genus Elaphurus Milne-Edwards, 1866, now represented solely by Père David’s deer (E. davidianus Milne-Edwards, 1866), exhibited considerable diversity during the Pleistocene of Eurasia, including the debated E. formosanus (Shikama, 1937) from the Middle Pleistocene of Tainan, Taiwan. The taxonomic validity of E. formosanus has been questioned due to incomplete material and morphological similarities with E. d. predavidianus Dong et al., 2019. Here, we describe new antler remains of E. formosanus from the Pleistocene of Taiwan and reassess the taxonomic status of the species. These fossils reveal diagnostic characters, including a shorter anterior beam, well-developed accessory tine structures, and a markedly reduced size compared to other Elaphurus species. Combined with geological age and paleobiogeographic evidence, these features support the recognition of E. formosanus as a valid, endemic species. Interestingly, our comparative analyses of antler size measurements further reveal that E. formosanus represents the smallest-bodied species, possessing an exceptionally diminutive stature among the genus. This finding, supported by multiple lines of evidence, suggests that this species underwent dwarfism, a condition documented for the first time in Elaphurus and representing the first dwarfed cervid species in Taiwan. The distinctive antler development also highlights the potential roles of sexual selection and paleogeography in shaping the evolutionary trajectory of this species. Our reassessment of E. formosanus not only provides additional evidence for the diversity of Elaphurus but also elucidates dwarf adaptation, antler evolution, and the declining diversity of the genus through the Pleistocene.

Estimates of the stratigraphical and paleogeographical ranges of fossil taxa depend on sample sizes, with the limiting case being a sample consisting of a single known specimen. The cnidarian order Conulariida Miller and Gurley, 1896 in the subphylum Medusozoa Petersen, 1979 comprises multiple genera that are represented by < 50 reposited specimens, in some cases from a single locality and stratum. The present note deals with two such genera, Galliconularia Van Iten and Lefebvre, 2020 and Glyptoconularia Sinclair, 1952. The former genus previously was known from the Lower Ordovician of the southern Montagne Noire in France; the latter was known from the Middle Ordovician of the central Moroccan Anti-Atlas (Van Iten et al., 2022) and from the Upper Ordovician of cratonic North America (Van Iten, 1994; Van Iten et al., 2022). Glyptoconularia was represented by < 12 reposited specimens, and Galliconularia was based on a total of 32 specimens.