Palaeoworld最新文献

The knowledge of the paleopathologies that affected large mammals during the Pleistocene of South America has increased in the last years, but most of the reported cases belong to the endemic clade Xenarthra. On the contrary, almost no case of diseases is known among representatives of other clades, such as Carnivora. Here we present and describe an inflammatory lesion in a left metacarpal IV assigned to the saber tooth Smilodon populator (Felidae) from the Late Pleistocene (ca. 100 ka; MIS 5) of Northeastern Argentina. The macroscopic and radiologic analyses reveal features consistent with chronic osteomyelitis, which in turn represents the first accurate record of an infectious process in a limb of this predator. This injury presumably caused lameness and loss of toe flexion, and considerably reduced the hunting abilities of this top predator, which used its robust forelimbs, particularly wide forepaws, and powerful back muscles to catch and bring down large prey.

Two partly anatomically preserved axes parallelly situated on a slab collected from an in situ volcanic ash bed called “Bělka” of the Whetstone Horizon, Kladno Formation (Pennsylvanian), Czech Republic, were studied in detail. Anatomically, both axes possess a C-shaped xylem strand with protoxylem tracheids situated on the convex side, demonstrating an inversicatenalean-type anachoropterid affiliation. They are further suggested to belong to one biological species, as they share a number of similar characteristics and common structures. Systematically, one of the two studied axes retains a primitive form of foliar anatomy with the oldest known anachoropterid plant (Anachoropteris sp.) in having two rather short lateral arms compared to the long median region. Although lacking foliage information, both axes likely belong to the rachis part of Discosoropteris zlatkokvacekii Pšenička, Zhou, Boyce, Votočková Frojdová, Bek and Wang, a fern species that was recently established based on the same slab where the two studied axes were preserved. Such a combination may further indicate the presence of a new family in the late Paleozoic anachoropterid plants. In addition, selected anatomically preserved ferns from the Whetstone Horizon were reviewed, which promotes a better understanding of the anatomical variability of fern species.

A well-preserved radiolarian assemblage was recovered from the Upper Jurassic section near the Rybaki village, Moscow Region, Central Russia. The radiolarians were found within the Amoeboceras serratum ammonite zone (upper Oxfordian), in phosphatized body chambers of ammonite shells. The radiolarian assemblage is represented by 23 species of 11 genera and displays Boreal affinity. It is characterized by abundance of Praeparvicingula: P. blackhorsensis (Pessagno and Whalen), P. donnae Bragin, P. elementaria (Carter), P. enormis (Yang) and by presence of the characteristic boreal family Echinocampidae (genera Echinocampe and Nordvikella). Five new species are described.

The Bajocian–Oxfordian Dalichai Formation of the Binalud Mountains (northeastern Iran) consists of marls, marly limestones and limestones that were sampled and studied in detail for their palynomorph and ammonite contents. Palynological studies enabled differentiation of three marine biozones (Cribroperidinium crispum, Dichadogonyaulax sellwoodii, and Ctenidodinium continuum) within the lower interval of the formation. The palynofacies analysis shows a gradual sea-level rise during the depositional period of the rock unit, while terrestrial palynomorphs (spores and pollen grains) revealed a predominantly tropical climate for the time interval. Furthermore, a large number of ammonites were recovered from the formation, based on which 12 families, 22 genera, 30 species and 12 biozones (Zigzag, Aurigerus, Retrocostatum, Discus, Bullatus, Gracilis, Anceps, Coronatum, Athleta, Transversarium, Bifurcatus, and Bimammatum) were differentiated. When comparing the dinoflagellate cyst zones with the ammonite zones, the Dichadogonyaulax sellwoodii dinoflagellate cyst zone was correlated with the ammonite zones of Zigzag, Aurigerus, Retrocostatum, Discus, Bullatus, and Gracilis and the Ctenidodinium continuum dinocyst zone was correlated with the Gracilis and Anceps ammonite zones. The dinocyst and ammonite assemblages of the Binalud Mountains are similar to assemblages described from northern and northeastern Iran (Alborz and Koppeh-Dagh basins) as well as Northwest Europe. This suggests marine connections between these sedimentary basins during the Bajocian–Oxfordian. Consequently, the integrated dinocyst and ammonite zonation established here can be utilized also in other parts of the northern Tethyan Realm. The diachroneity of the upper boundary of the Dichadogonyaulax sellwoodii Zone between the Binalud Mountains and Northwest Europe is however revealed by comparison with the ammonite zones.

In a strict sense, palaeoscolecids are a group of cycloneuralian worms (ecdysozoans) characterized by the tessellation of trunk sclerites, which are differentiated into plates, platelets, and microplates. The Wangcun section in western Hunan, South China, which represents the Furongian Series (upper Cambrian), has yielded a rich and diverse collection of palaeoscolecids. However, there is uncertainty about how the morphology and arrangement of their sclerites change during ontogeny and the potential taxonomic implications of these changes. Here, we report new phosphatized trunk fragments from the Wangcun section, which are assigned to Dispinoscolex decorus, Hunanoscolex campus (= Ornatoscolex hunanensis), and Schistoscolex hunanensis. Trunk fragments of the same species with different diameter indicate the presence of several ontogenetic stages, and careful assessment revealed two types of sclerite growth patterns. One is represented by D. decorus and possibly also by S. hunanensis, in which the worm growth is accompanied mainly by the enlargement of the plates, with almost no change in the median annular zones and annulation boundaries. The other type is represented by H. campus, in which the worm growth is accompanied mainly by the widening of the median annular zones and annulation boundaries inserted with continuously more platelets and microplates. Because the specimens originally assigned to H. campus seem to represent late ontogenetic stages of O. hunanensis, we propose that H. campus is a senior synonym of the latter. This study underscores the importance of ontogenetic variation of sclerites for the taxonomy of palaeoscolecids, and highlights the significance of Orsten-type fossils in the study of metazoan ontogeny.

A comprehensive record of unique and endemic species of “Giraffa” priscilla has been documented and reported from the Chinji Formation of Lower Siwaliks, Pakistan. The material comprises incisors, canines, premolars, molars, mandibular and maxillary fragments which have been recovered from the Middle Miocene localities of Dhok Bun Ameer Khatoon, Rakh Wasnal, Bhelomar, and Lawa, Punjab, Pakistan. “Giraffa” priscilla is a primitive species of giraffids, having a broad crown, strong styles, and median ribs.

The Naqing section in Luodian (Guizhou, South China) contains a deep-water carbonate-dominated succession of the Late Devonian through the Permian. In this study, 72 conodonts species/subspecies of 11 genera were obtained from the lower part of this section including. Seven middle to late Famennian and four early to late Tournaisian conodont biozones were recognized as, in ascending order, Palmatolepis marginifera marginifera Zone, Palmatolepis marginifera utahensis Zone, Polygnathus granulosus Zone, Palmatolepis rugosa trachytera Zone, Polygnathus styriacus Zone, Palmatolepis gracilis manca Zone, Palmatolepis rugosa rugosa Zone, Siphonodella isosticha Zone, Gnathodus punctatus Zone, Gnathodus typicus-Gnathodus cuneiformis Zone, and Gnathodus typicus-Protognathodus cordiformis Zone. Several key conodont biozones across the Devonian–Carboniferous Boundary (DCB) interval found elsewhere are not discovered in the Naqing section, likely due to a conodont-barren interval in the siliciclastic facies. The middle Famennian–late Tournaisian conodont biozones illustrated in this study provide a robust chronostratigraphic framework for further research on biotic and paleo-environmental events during the Late Devonian through Early Mississippian critical greenhouse-icehouse climate transition.

Phu Kao-Phu Phan Kham Mountain ranges, situated on the border of Nong Bua Lamphu, Udon Thani, and Khon Kaen provinces, northeastern Thailand, bear several localities that yield dinosaurs and other vertebrate faunas in the Lower Cretaceous. However, this area has received relatively little attention from the scientific community and the public. Here we review and report new dinosaur materials recovered from this region, some found decades ago, others discovered recently. We identify and discuss their taxonomy and paleobiodiversity. In the Barremian Sao Khua Formation, theropod dinosaurs were represented by spinosaurids, an early branching megaraptoran, a large indeterminate theropod, and small indeterminate theropods. Sauropods were represented by an indeterminate sauropod, a neosauropod, and titanosauriforms, including probable brachiosaurid and non-titanosaur somphospondylans. Other vertebrate groups, including crocodilians, turtles, fishes, and sharks, indicate a similar composition to other Sao Khua Formation communities in northeastern Thailand. The Sao Khua vertebrate assemblage exhibits the taxonomic diversity of dinosaur fauna and is currently the best-documented assemblage in the Early Cretaceous of Southeast Asia. The Aptian–Albian Khok Kruat Formation, however, yields less diverse vertebrates. They are represented by freshwater sharks, crocodilians, and spinosaurid theropods. This may be due to sampling bias, environmental, or taphonomic conditions. This study provides the basis for future paleontological exploration and research of Mesozoic vertebrates in northeastern Thailand.

During recent years, different studies have focused on characterising plant diversities in the Carboniferous environments of the Variscan Foreland. One of these areas, the Nord-Pas-de-Calais Coalfield, has a Namurian–Westphalian sequence that has historically yielded abundant evidence of vegetation change, but to date, little attention has been paid to its macrofloral diversity dynamics. Here we show, for the first time, a comprehensive characterisation of the diversity changes and macroevolutionary patterns from this coalfield. The results show evidence of low levels of species richness during the Namurian, followed by an exponential diversification at the base of Westphalian. Duckmantian–Bolsovian species diversity continues to progressively increase, suggesting relatively stable conditions at that time. Maximum species richness is observed at the mid-Bolsovian followed by a major depletion during the Asturian. Overall, this pattern is quite similar to that seen in other parts of the Variscan Foreland. However, we see Nord-Pas-de-Calais vegetation diversified earlier than those in the British parts, probably because the dynamics of marine incursions and lacustrine conditions delayed its development in the latter areas. Furthermore, we also see the Asturian decline of the Nord-Pas-de-Calais coal swamp occurred later than in other basins, such as in the Pennines, Ruhr, and South Wales. This scenario suggests that the collapse of this biome was probably caused by increased sediment influx and reduced subsidence, resulting from the northwards migration of the Variscan Mountains. This further supports other studies in Europe advocating that climate change was at most only a subsidiary factor in the collapse of the Pennsylvanian coal swamp biomes.