The study is the first attempt to explore variation of the size and shape of the palatine bones and choanae in Ursus kanivetz Vereshchagin, 1973, and Ursus rossicus Borissiak, 1930, as well as in a large comparative sample of modern Ursidae. The height and width of the choanae were measured in CT images of the skulls of cave and modern bears. The absence of sexual dimorphism in the size of choanae in cave bears has been statistically determined. The indices of the relative sizes of the palatine bones and choanae in modern and cave bears have been calculated. For the first time, reliable data on a high level of correlation between the shape of the palatine bones and the average temperature of the coldest month were obtained for representatives of the Ursidae. At the same time, it was found that the correlation of the choanae size index with the average temperature of the coldest month is not so high and does not reach the level of statistical significance. The results of the study can complement the understanding of the physiological features of the respiratory system of cave bears.
This paper describes four incomplete specimens from the Late Oligocene deposits of Poland. One of these, containing highly diagnostic bones, is described as a new species of Suboscines within Passeriformes, another likely also belongs to Suboscines, and the remaining two, although they possess articulated elements, are too poorly preserved to be assigned to any bird group and have been identified as Aves indet. To date, all new passerine taxa from the Paleogene of Europe have been found in Early Oligocene (Rupelian) deposits. Significantly fewer specimens are dated to the Late Oligocene (Chattian). The only passerine from this period with preserved articulated bones is a severely damaged foot; the remaining specimens consist of isolated bones. Therefore, the new passerine species described in this paper provides valuable data closer to the Neogene, helping to fill a gap in our knowledge and potentially documenting later stages of early passerine evolution. Its scientific value is all the greater because it has associated bones that may be helpful in future phylogenetic studies. The manuscript also summarizes our knowledge of Oligocene birds from the northern part of the Carpathian Arc. In addition to the numerically dominant Passeriformes, repformes, Accipitriformes, and Piciformes are also known. Recent research has shown that the deposits from the Jamna Dolna 2 site, originally dated to the Early Oligocene, actually date to the Late Oligocene, which requires a correction of the ages of several previously described bird species.
The extinct megatooth shark, Otodus megalodon, is an iconic Neogene shark that may have reached as much as 24.3 m in total length (TL). The 24.3 m TL estimate was partly based on published photographs of an associated set of vertebrae from the Upper Miocene Gram Formation in Gram, Denmark, some of which allegedly had a diameter of 23 cm. Here, we report on the rediscovery of the specimen, which was thought to be lost, confirming the reported maximum diameter of 23 cm. Those vertebrae co-occurred with remains of a cetorhinid (basking shark), but the morphology and size assessments of the vertebrae suggest that they belong to O. megalodon, with the possibility that the cetorhinid remains represent stomach content of the megatooth shark. The vertebral specimen of O. megalodon was also used to decipher its ontogenetic growth patterns, and this study suggests that this specific individual had the potential to grow even slightly larger than 24.3 m. However, the growth model presented in this work must be viewed as highly tentative. Nevertheless, the O. megalodon specimen described herein is significant because it represents the largest shark vertebral specimen known to date, and quite possibly even the largest non-tetrapod vertebrae ever recorded. Ultimately, a more complete skeletal specimen of O. megalodon, ideally with associated teeth, is required for any further discussion on the maximum possible size of the fossil species.
From Middle Miocene Dominican amber (15 to 20 million years old) a new type of caterpillar was detected and is described here as a new taxon. The most peculiar character are its stemapods, prolonged anal prolegs, which do occur in the extant family Notodontidae. Phenotypic similarity to an extant trap-catch from the Neotropics affiliated via DNA barcoding served in family recognition of the fossil. The adults of Notodontidae, commonly known as Prominent Moths, are typically nocturnal moths with caterpillars mostly feeding externally on leaves of trees and bushes. For the new fossil caterpillar tripod-like setae at the end of the stemapods may indicate a tactile role in hind direction, rather than in locomotion. The new find is the first fossil notodontid caterpillar which has ever been described.
The Santa Maria Amajac area in Hidalgo, Mexico, is a noteworthy zone for the study of the past biodiversity of central Mexico. Through the years, geological and paleontological studies have demonstrated that during the late Pliocene in what is now the Santa Maria Amajac area there was an intermountain paleolake with a remarkable diversity of flora and fauna, as shown by the description of several new species of fossil oaks, a new species of beetle, a diatom, and a goodeid fish, plus many other records of terrestrial and aquatic plants, vertebrates and invertebrates. Among the microvertebrate fauna are numerous specimens of fossil amphibians, but these were so far unstudied. We describe a new species of fossil axolotl, Ambystoma quetzalcoatli sp. nov., based on some complete and articulated specimens from the Sanctorum fossil site of the Santa Maria Amajac area. The taxonomy of A. quetzalcoatli suggests that it is closely related to the extant species from the central part of the Trans-Mexican Volcanic Belt and may belong to the tiger salamander group. Additionally, this is the oldest known record for the genus Ambystoma in Mexico.
New insect eggs attributed to the genus Palaeoaldrovanda are described, based on two specimens recovered from the Upper Cretaceous sedimentary deposits (upper Coniacian), exposed in the Mina site close to the small village of Seadouro, situated in the Beira Litoral region, western Portugal. The insect fossil eggs are small, about 1.5-1.7 mm long and 0.9-1.2 mm broad, ovoid in outline shape and characterized by the possession of an elongated neck-like structure in the basal part and by a cap-like projection with irregularly pitted surface in the apical part. The outer surfaces of the fossil specimens show indistinct, longitudinally arranged, rectangular cell-like structures. The presence of distinctive characters, such as wall structure and shapes of projections indicate that the fossil specimens are insect eggs. The new fossil insect egg belongs to the genus Palaeoaldrovanda. The type species Palaeoaldrovanda splendens is emended here. The new material is assigned to a new species, Palaeoaldrovanda seadouroensis. The genus Palaeoaldrovanda was previously reported from the Late Cretaceous (late Turonian-Santonian) of Central Europe, and the new species Palaeoaldrovanda seadouroensis represents the first record of the genus from the Late Cretaceous deposits in the Iberian Peninsula, adding to our knowledge of the past diversity and geographic distribution of the genus. While numerous varieties of insect eggs from various species look superficially like seeds, no existing group precisely matches the unique traits of this fossil material. Therefore, it has not yet been possible to classify it precisely.
We report on the last species of Ambassidae from the European Cenozoic and describe a new genus and species, Neodapalis haraldahnelti n. gen. et n. sp. The type specimens were collected at a location along the Zmajevac Stream in the Valjevo-Mionica Basin (Serbian Lake System). Neodapalis haraldahnelti is described based on a well-preserved skeleton with otolith in situ from freshwater sediments of the Middle Miocene (Sarmatian) and an isolated skull. Neodapalis differs from all known ambassid genera in having 11 abdominal vertebrae and six ventral-fin rays, and from all extant genera in the presence of three supraneurals; among fossil taxa, only Dapalis shows comparable variation in supraneural number. Most species of the related genus Dapalis from freshwater deposits of Europe are based on otoliths, while species based on articulated skeletons are more rare, particularly those with otoliths in situ. Until now, all confirmed species of Dapalis have been documented from Oligocene to Early Miocene age of European freshwater and brackish water systems with a few notable exceptions of otolith-based species from other continents. No ambassid species has previously been described from the upper Middle Miocene lacustrine sediments. Our findings significantly contribute to the understanding of the evolutionary history of fossil Ambassidae fishes.
The poor sampling of Late Devonian fossils in Gondwana prevents a full understanding of the diversification patterns of the main vascular plant groups that are ancestral to extant lineages, such as the different pteridophyte-grade lineages. Among these are the Iridopteridales, a group with architectural features comparable to those of the sphenophytes. The Famennian locality of Barraba in New South Wales has yielded a diverse plant assemblage, among which Keraphyton represents the first iridopterid genus recorded in Australia. In this paper, two anatomically preserved fragments of axes from Barraba are assigned to a new species of Keraphyton, K. talentii, and an emended diagnosis of this Australian genus is provided. The axes of K. talentii differ from K. mawsoniae in their smaller size, a primary vascular system organized around three fundamental ribs connected centrally, instead of four in K. mawsoniae, and a smaller number of ultimate ribs. The aerenchymatous cortex observed in some parts of K. talentii suggests that this species was able to live in temporarily, if not permanently, wet habitats. Keraphyton axes are characterized by a deeply lobed stele with a complex pattern of dissection, and protoxylem strands that tend to be exarch. The larger size of K. mawsoniae is associated with a higher number of primary xylem ribs, but the primary vascular system remains actinostelic and is not associated with the development of radially aligned tracheids. The new species increases the taxonomic diversity of the free-sporing plants that were already predominant in the permineralized plant assemblage of Barraba.
The biodiverse forests of southern Indochina face severe anthropogenic pressure, but understanding of their deep-time history remains limited due to the general lack of fossil evidence. Here, we present a new Plio-Pleistocene macrofossil flora from the ing 565 specimens of 44 morphotypes. The assemblage is dominated by dicotyledonous leaves with well-preserved venation or cuticles and is characterized by entiremargined leaves (with only one toothed morphotype) and relatively small leaf sizes (87% microphylls and notophylls). The flora, in rank order, has abundant Syzygium paceae) leaves, along with potential representatives from Fabaceae, Lauraceae, Phyllanthaceae, and Lecythidaceae. Both leaf physiognomy and floristic composition indicate that the Kon Tum flora represents a lowland seasonal tropical broad-leaved forest linked to extant regional forests. The diverse associated palynoflora supports this paleovegetation interpretation with mixed source environments and indicates a Pliocene to early Pleistocene age of deposition in a coastal, fluvial setting with tidal influence. The study site is currently at an elevation of over 500 m, indicating significant uplift since deposition. This study marks the first Cenozoic paleobotanical collection of southern Indochina and presents an ancient analog of the extant regional lowland monsoon forests, one of the world's most threatened forest ecosystems.
Fully aquatic whales (Pelagiceti) evolved and, possibly, diversified during the Middle Eocene, and one of the earliest records comes from Ukraine. Materials from the Pyvykha Mountain in the central part of Ukraine were revised: cetacean fossils came from the Middle Eocene (late Lutetian - Bartonian) deposits from outcrops at shores of the Kremenchuk water reservoir. Among them, there is an incomplete skeleton of a large whale and cervical and caudal vertebrae of another, smaller individual. The larger individual, most similar to whales assigned to Antaecetus from the Middle Eocene of Africa, includes a mandible fragment, several vertebrae, bones from the forelimb (humerus, radius, and ulna fragments), and a part of the innominate. Mandible fragments bear numerous mental foramina: that is an indication of vascularized lips which may suggest suction feeding of the whale. A pachyostotic innominate shows presence of a well-developed hind limb. Fully fused epiphyses of the smaller individual indicate that it could reach definitive body size. Thus, cetaceans of at least two different body size categories (5-6 m and 9-11 m long) co-existed in the same North Tethyan locality during the Middle Eocene. They show similarity to cetaceans from North African deposits of the same age and can be closely related to the ancestors of the crown group of modern whales, Neoceti.
The Asian continent is unique for its exceptional biodiversity and position as a biogeographic crossroads, resulting in considerable taxonomic, ecological, and morphological diversity. Asia is also notable for its complex geological and climatic history stemming from the collision of Eurasia with the Indian subcontinent, resulting in uplift of the Himalaya and Tibetan Plateau, which have gone on to influence local and global climatic change over millions of years. The effects of these events on biotic assemblages have not been comprehensively investigated, and consequences for mammalian assemblages are unclear. Asian biodiversity is preserved in a rich and well-studied Cenozoic fossil mammal record which offers the opportunity to examine the patterns of Asian rodent biodiversity in response to significant geological and climatic events. In this study, we investigate morphological and ecological diversity in response to Tibetan Plateau uplift and subsequent changes to monsoon circulation during the early Miocene, the aridification of central Asia during the late Miocene, and the intensification of dust transport during the Pliocene-Pleistocene. We first present a large dataset of rodent taxonomic, morphological, and ecological diversity. We then examine site dissimilarity and multivariate ecomorphospace change before and after key geologic and climatic events. We find distinct ecomorphospace occupation in most time stages with contraction across periods of aridification and expansion during periods of increased dust transportation. We conclude that ecomorphological diversity responds to environmental drivers and is detectable in the fossil record of Asian rodents, suggesting that large-scale landscape and climatic shifts have had important influences on mammalian evolution.
Fossils preserved on high aspect-ratio slabs of matrix ('plate-like' or 'slab' fossils with one short axis and two longer axes) include some of the most complete and scientifically significant vertebrate fossils ever discovered. These plate-like fossils are problematic to scan using conventional lab-based X-ray computed tomography (CT) for two reasons: 1) poor penetration of X-rays through the long, flat axis of the matrix slab leads to photon extinction imaging artefacts, and 2) resolution is limited by the distance required for the specimen to complete a full rotation avoiding collision with the X-ray source. One potential solution to these issues, which has yet to be thoroughly explored, is limited-angle computed tomography (LACT), a technique which involves rotating the specimen through an angle less than the full 360 degrees typically used in labbased CT. Here, we demonstrate LACT on a fossil specimen for the first time, highlighting the effects of adjusting angular sampling on scan quality. Although small angles of rotation result in significant imaging artefacts using conventional reconstruction methods (e.g., filtered back-projection), we find these artefacts are minimised at angles of rotation greater than 180 degrees. The relative benefits of LACT are dependent on the purpose of the scan and the shape, size, and material of the specimen, with potential advantages including increased resolution and reduced photon extinction artefacts. We present scenarios in which using LACT over conventional CT to scan plate-like fossils should be considered, taking advantage of a relatively simple alteration to the scanning process to improve imaging results for these problematic specimens.
This study reports two semi-articulated tetraodontid pufferfish fossils from the Liuchungchi Formation of the Niubu area, Chiayi County, southern Taiwan (Early Pleistocene; formation-level age similar to 1.95-1.35 Ma). The material comprises an almost complete skull and fragmentary viscerocranial elements and is housed in the Chiayi Municipal Museum. The assignment of Tetraodontidae is supported by the characteristic beaklike jaws composed of discrete premaxillary and dentary elements with prominent midline interdigitations, together with associated dermal spinules. Comparative assessment of the opercular series, suspensorium (including the pterygo-quadrate complex), and neurocranial proportions supports the assignment to the extant genus Arothron Muller, 1841. These specimens represent the first fossil record of Arothron and the first tetraodontid record from Taiwan, and they provide a rare data point for tetraodontiform cranial preservation in the western Pacific, expanding the taxonomic coverage of Taiwan's fish fossil record.
The bryozoan assemblage from the Upper Paleocene (Thanetian) deposits of the Turgay Trough in northern Kazakhstan is described and illustrated for the first time, employing a combination of high-resolution X-ray microtomography (& micro;CT) and scanning electron microscopy (SEM). The material, collected from the Sokolovsky section, comprises a diverse association of cyclostome and cheilostome bryozoans, most preserved as encrusting colonies on a variety of bioclasts, including mollusk shells, serpulid tubes, barnacle plates, and fragments from other bryozoan colonies. In total, twentythree species are recognized, of which five are new: Voigtopora naidini sp. nov., Amphiblestrella magna sp. nov., Distansescharella levinae sp. nov., Hexacanthopora turgayensis sp. nov., and Brydonella favorskayae sp. nov. Additionally, several taxa are described in open nomenclature and are tentatively assigned to the genera Proboscinopora, Mesenteripora, and Iyarispora. Together with Oncousoecia, Cavarinella, and Brydonella, these genera are recorded here for the first time from Thanetian deposits. The assemblage is dominated by encrusting, multiserial, unilamellar colonies, indicative of a shallow but turbulent marine environment with firm substrates suitable for colonization. Most taxa exhibit close affinities to coeval bryozoan faunas from the North Atlantic region. These biogeographic similarities suggest faunal exchange between the Tethyan and Boreal realms during the late Paleocene. The new data considerably expand the known stratigraphical and paleogeographic range of several bryozoan genera, and provide important insights into the post-Cretaceous recovery, diversification, and dispersal of bryozoans following the end-Maastrichtian extinction event.
Although stegosaurs have a long history in Europe, they were first discovered in Spain only in the late twentieth century. Since then, discoveries have increased markedly, particularly in the provinces of Teruel and Valencia (eastern Spain). In this work, several new specimens from the Villar del Arzobispo Formation are systematically studied. Recovered from nine fossil sites, they are referred to as Stegosauria indet., Neostegosauria indet., and Dacentrurinae indet., thereby expanding the known stegosaurian record. The Spanish 'historical material' is also revisited and systematically reassessed, revealing that this collection is currently dispersed across several institutions and collections. Furthermore, the review of all known specimens from the region results in the taxonomic reassignment of additional material. The stegosaurian record is exclusively composed by dacentrurines, which exhibit high morphological homogeneity. Four specimens can be attributed to Dacentrurus armatus, with no current evidence for additional dacentrurine species or the presence of stegosaurines. The abundance of D. armatus and indeterminate dacentrurine remains suggests these stegosaurs were very common and firmly established in the Late Jurassic coastal ecosystems of eastern Iberia. In contrast, the absence of stegosaurines likely reflects ecological preferences for inland biotopes, together with fossilization bias. The richness and good preservation of both osteological and ichnological record make the eastern Iberian Peninsula one of the most important regions worldwide for the study of these dinosaurs.
Braconidae, a highly diverse family of ichneumonoidean wasps, comprises over 21,000 described species. These parasitoid wasps are of growing interest in biological pest control due to their role in regulating insect populations. A new syninclusion in Baltic amber presents a female braconid wasp alongside a silvanid beetle larva. Detailed morphological analysis assigns the wasp to Braconidae; possibly a representative of Brachistinae - Brachistini. The beetle larva is identified as Telephanini within Brontinae, Silvanidae. This finding represents the first larval fossil record of Silvanidae and provides a rare case of entanglement of two biosyninclusions within amber, a fossil parasitoid wasp and a beetle larva. We discuss the morphology, ecological roles, and evolutionary history of these insect groups. The entangled preservation of the wasp and larva supports at least their coexistence in the same ecosystem and interaction at the moment of entrapment. This finding contributes valuable insights to the study of palaeoecology.
