After more than 65 years, new well-preserved specimens of the Ladinian (Middle Triassic) Xingyi Fauna allow the redescription of the miniature peltopleuriform fish Habroichthys orientalis (Su 1959). This taxon was previously identified as Peltopleurus, but this revision highlights the diagnostic characters typical of Habroichthys. Namely, the single deep flank scale row with a final semicircular scale, the often completely fused skull roof, the thin maxilla not sutured to the stick-shaped preopercle, and the lack of teeth. For the first time in a Triassic fish, a µ-CT scan has been used to study the 3D shape of the in situ otoliths. Some peculiar features of the genus are confirmed, such as the stiff shield-like skull roof frequently found isolated and the sexually dimorphic anal hooklets likely used during mating. Juveniles and growth lines on adult scales show the presence of an ontogenetic series, with implications also for the paleoenvironmental restoration of the area. Morphological comparison revealed H. orientalis to be most similar to H. dincae from the almost coeval Pelsa/Vazzoler Lagerstätte in the Dolomites. Their presence on opposite sides of the Paleo-Tethys suggests multiple West–East population interchanges (the so-called “Triassic Silk Road”) rather than a single migration event that could previously have been hypothesized based on the Anisian appearance of the genus in Slovenia and in southern China.
Jelle J.A. Heere, Jonathan J.W. Wallaard, Maarten De Rijke
et al.
The family Dercetidae comprises a diverse array of marine aulopiform actinopterygians. Until now, merely seven specimens, assigned to five species, were recorded from the Maastrichtian type area. Here, around two dozen dercetid fossils, originating from a number of quarries and outcrops in north-eastern Belgium and the south-eastern Netherlands are described and illustrated. This material comprises two new genera, Beukidercetis gen. nov. and Petrodercetis gen. nov., and four new species: Caudadercetis taverni sp. nov., Beukidercetis lissus gen. et sp. nov., Cyranichthys sideralis sp. nov., and Petrodercetis bidirectus gen. et sp. nov. Newly collected specimens of Cyranichthys jagti, Dercetis triqueter and Ophidercetis italiensis are also added, because these extend their respective stratigraphical ranges in the study area. Moreover, material here assigned to Dercetoides venator and a specimen resembling Cyranichthys ornatissimus markedly expand their geographical and stratigraphical ranges. In general, the present material reflects an underappreciated diversity of dercetids in the Maastrichtian type area, even though that they fossilize well compared to other late Maastrichtian actinopterygians from the study area. This high degree of preservation may be related to a benthic lifestyle, or to their slender, scute-covered bodies that may have been less vulnerable to disruption than those of other actinopterygians.
Lea D. Numberger-Thuy, Manuela Aiglstorfer, Dominique Delsate
et al.
Abstract The Triassic-Jurassic (T/J) boundary witnessed one of the five major mass extinctions during the Phanerozoic, paving the way towards the evolution of modern ecosystems. However, the study of biotic change during this interval is hampered by the scarcity of outcrops exposing the T/J-boundary without major interruptions or abrupt facies change. Here, we present a previously undocumented succession of Rhaetian (Upper Triassic) to Hettangian (Lower Jurassic) strata, exposed on two sections along the banks of the river Prüm near the town of Irrel, Rhineland-Palatinate, Germany. The new succession holds an unusual palaeogeographic position squeezed between the Rhenish and London Brabant (including the Ardennes) massifs, thus filling a gap in the T/J-boundary record of the Central European Basin. It includes some unusual facies such as a thick and highly fossiliferous, conglomeratic bonebed close to the top of the middle Rhaetian and bituminous black claystones in the middle Hettangian. Finally, it stands out in yielding well preserved fossils of taxa that are rare or undocumented in the region. We provide a comprehensive account of the lithostratigraphy of the new succession and assess its biostratigraphic framework using ammonite, ostracod and palynomorph occurrences.
Alejandro G. Kramarz, Eduardo S. Bellosi, Mariano Bond
et al.
Abstract The Collón Cura Formation (CCF) bears a diverse assemblage of middle Miocene terrestrial mammals (the Colloncuran fauna) known from the end of XIX century. The CCF along with the La Pava Formation (LPF) constitutes the main syntectonic infill of intermontane basins in the extra-Andean NW Patagonia. The study of paleosols and terrestrial ichnofacies of both units in these basins, particularly in the Jacobacci basin (Rio Negro Province, Argentina), document the progressive environmental change since the end of the Miocene Climatic Optimum, related to the drying and cooling of southern South America. This change is recognized in the andic Mollisols and mollic Andisols bearing Coprinisphaera ichnofacies formed in subhumid grasslands or wooded-savannas (LPF), and in the xeric-vertic Andisols and andic Aridisols bearing Celliforma ichnofacies developed in semiarid woodlands or bushlands (CCF). However, a new U–Pb date of 14.38 ± 0.19 Ma (late Langhian), for the LPF at the Huahuel Niyeu valley in the Jacobacci basin, indicates that both landscapes co-existed likely following a vertical rainfall gradient (orographic precipitation). In the present work, we report the first mammals from the LPF recovered from the Huahuel Niyeu River associated with the dated strata. They include Palaeothentes intermedius, Prozaedyus sp., Proeutatus sp., Propalaehoplophorinae indet., Glossotheriopsis pascuali, Massoiamys obliquus, Pliolagostomus friasensis, Eusigmomys cf. E. oppositus, Pachyrukhos moyani, Hemihegetotherium tantillum, Protypotherium australe, Protypotherium praerutilum, Palyeidodon obtusum, Hyperoxotodon sp. nov, Toxodontidae indet., and Astrapotheriidae indet. All these taxa (except P. intermedius) also occur in roughly coeval sediments of the CCF in Jacobacci and other basins of NW Patagonia. We conclude that the heterogeneous landscape developed in Jacobacci basin was inhabited by diverse functional groups of Colloncuran mammals adapted to different climatic and floristic settings, and therefore they are not sensitive to small-scale environmental heterogeneity. These palaeoecologic inferences could be extended to other Miocene basins and to other Cenozoic mammal faunas of Patagonia, which paleohabitats were generally deduced from feeding behaviors.
In this contribution, we report and describe a microvertebrate fossil assemblage recovered from a Holocene fluvial unit located in Entre Ríos Province, northeastern Argentina (Mesopotamian Region). The analyzed stratigraphic section is on the left bank of Doll creek (32° 18’ 24” S, 60° 25’ 41” W), southwestern Entre Ríos Province. The stratigraphic section was divided into three levels and a total of 36 samples were collected. Radiocarbon dating was obtained from gastropod shells from the base of the section, with a range of 9,990±140 BP (Early Holocene). It was possible to record fishes, such as eels and characids, anurans, reptiles, birds, and small-medium size mammals. Most of the identified taxa constitute the first fossil records from the Quaternary of the Mesopotamian Region and even from Argentina. The systematic, biostratigraphic, and taphonomical results show that the environmental conditions in this area at the beginning of the Holocene period were similar to the current ones: a temperate-humid climate with water availability. This contribution is the first study of a microvertebrate fossil assemblage from the Early Holocene from northeastern Argentina (Mesopotamian Region) and represents an important contribution to the knowledge of the Quaternary fossil vertebrates from Argentina.
Daniela Elizabeth Olivera, Marcelo Adrián Martínez, Germán Otharán
et al.
The perforated Pediastrum Meyen s.l. species are recorded for the first time in the basal levels of the Tithonian Vaca Muerta Formation, extending its first stratigraphical record to ages as old as Late Jurassic times. Based on the ecological requirements of Pediastrum simplex var. clathratum and P. simplex var. biwaense, the previously warm paleoclimatic conditions suggested by the Late Jurassic of Neuquén Basin, are reinforced. The co-occurrence of the different mechanisms that interacted during the transport, accumulation, and early diagenesis of these sediments and their organic content would have allowed for the excellent preservation of the Pediastrum Meyen s.l. species.
En esta contribución se dan a conocer nuevos registros de mamíferos del Pleistoceno Tardío de la Provincia de Entre Ríos. Los fósiles provienen de la Formación Salto Ander Egg, una unidad depositada en los valles fluviales del sudoeste entrerriano con una edad, obtenida por OSL, entre los 120 ka y los 60 ka. Se interpreta que las secuencias de la formación fueron acumuladas durante el MIS 5. El contenido paleontológico de la unidad constituye el registro que mejor caracteriza el inicio del Pleistoceno Tardío para América del Sur y la transición MIS 5e-MIS 5c. En este trabajo se describen 12 taxones: cf. Ozotoceros bezoarticus (Cervidae), Morenelaphus cf. brachyceros (Cervidae), Hemiauchenia paradoxa (Camelidae), Lama guanicoe (Camelidae), Mylodon darwini (Mylodontidae), Glossotherium robustum (Mylodontidae), Lestodon armatus (Mylodontidae), Glyptodon reticulatus (Glyptodontidae), Panochthus tuberculatus (Glyptodontidae), Eutatus seguini (Dasypodidae), Notiomastodon platensis (Gomphotheriidae) y Toxodon platensis (Toxodontidae). La mayoría de ellos son nuevos registros y constituyen ejemplares más completos que los previamente conocidos para la unidad. Mylodon darwini es el primer registro en la Formación Salto Ander Egg y extiende ampliamente su distribución geográfica en la provincia. Además, se da a conocer una nueva localidad fosilífera correspondiente al Arroyo El Bellaco (Departamento Diamante) y se incrementa notablemente el número de registros para el sitio Arroyo El Pelado que hasta el momento se conocía por solo tres hallazgos.
We have tested different preparation and photographic methods to define a protocol for UV analysis of fossil specimens.
We also have explored its main applications while analysing specimens from different stratigraphic contexts, of different
biomineralogical composition, and belonging to different fossil groups (including invertebrates and vertebrates). We
have photographed specimens using a camera equipped with appropriate lens and filters both in visible light and with
flashlights at two wavelengths: the 365 nm UV light and the 440 nm visible violet spectrum, the latter here tested for
the first time. Our results indicate that bleach treatment is not recommended for calcite-shelled brachiopods, while it is
suggested for aragonite-shelled molluscs. We show that photography in the ultraviolet and visible violet spectra are useful
tools enhancing the recognition of morphological characters and colour patterns and allowing to distinguish soft-bodied
fossils from the matrix. Also, it allows to discern specimen areas embedded in the sediment from those exposed to sunlight, which is helpful to reconstruct the conditions experienced by fossils. However, the mineralogy of the biomineral
affects UV responses, as morphological characters of calcite shells are better emphasized with the 440 nm wavelength
(visible violet spectrum), whereas those of aragonite, bioapatite and phosphatized specimens with the 365 nm (ultraviolet
spectrum); also, shell microstructures with their different crystal arrangement and elemental incorporation may cause
different reactions, whereas the stratigraphic context affects specimen preservation influencing pigment preservation.
We thus provide a protocol for photography in the ultraviolet and visible violet spectra and show that this technique
has a high potential in palaeontology, having no limitations for its application in invertebrate or vertebrate specimens.
JORGE A. HERRERA-FLORES, THOMAS L. STUBBS, FRANCISCO SOUR-TOVAR
We reexamine and redescribe the type specimens and other associated material of the Late Jurassic rhynchocephalian
Opisthias rarus, from Quarry 9 of the Morrison Formation. We rediscover and describe a fragment of rock matrix belonging
to the holotype that is presented for the first time, and we also comment on undescribed material from Quarry 9 that
possibly belongs to an unnamed species of Opisthias. In addition, we describe a new specimen of Theretairus antiquus
that helps to reject its proposed status as a junior synonym of O. rarus, and contributes to increase the knowledge of the
microvertebrate fauna of the Late Jurassic of North America.
For several decades, a debate has been waged over how to interpret the significance of fossils from the Burgess Shale and Cambrian Explosion. Stephen Jay Gould argued that if the “tape of life” was rerun, then the resulting lineages would differ radically from what we find today, implying that humans are a happy accident of evolution. Simon Conway Morris argued that if the “tape of life” was rerun, the resulting lineages would be similar to what we now observe, implying that intelligence would still emerge from an evolutionary process. Recent methodological innovations in paleontological practice call into question both positions and suggest that global claims about the history of life, whether in terms of essential contingency or predictable convergence, are unwarranted.
OBJECTIVES Kranioti, Grigorescu, and Harvati have recently described (PLoS One 2019, 14(7),e0216718) the breakage to the Cioclovina 1 earlier Upper Paleolithic cranium as indicating fatal interhuman blunt trauma. We have reassessed their analysis in terms of the specimen's condition at discovery, its current condition, and the post-discovery history of the cranium. MATERIALS AND METHODS The original Cioclovina 1 neurocranium and currently associated pieces were visually assessed for the nature of the damage to them, and the records of its discovery, the original 1942 photographs, and their subsequent history in Bucharest were reviewed. RESULTS The damage to Cioclovina 1, attributed by Kranioti and colleagues to perimortem blunt trauma, was not present at the time of its 1940-41 discovery in the Peştera Cioclovina Uscată. The "trauma" is from the World War II bombing of the University of Bucharest and subsequent attempts to restore the cranium. The damage does not, and cannot, document interhuman violence in the Pleistocene. CONCLUSIONS Although other cases of antemortem and perimortem trauma are known from the earlier Upper Paleolithic, and Pleistocene humans more broadly, there is absolutely no evidence of perimortem trauma on the Cioclovina 1 cranium. Proper assessment of levels and patterns of human trauma in the Pleistocene must be based on the correct paleontological, taphonomic, and historical assessment of the fossil remains in question.
Se presenta el estudio sistemático de las esporas y formas algales recuperadas de la Formación Río Turbio, Eoceno medio–tardío de la Cuenca Austral. Se describen algas de agua dulce, briofitas, helechos y licofitas. Closterium sp. cf. C. thailandicum Songtham et al., Botryococcus sp., Coelastrum sp. 1, Catinipollis eiseltalensis Krutzsch, Bryophyta s.l. sp. 1, Kuylisporites waterbolkii Potonié, Matonisporites sp.1, Foveotriletes sp. 1, Polypodiisporites perverrucatus (Couper) Khan y Martin, Klukisporites scaberis (Cookson y Dettmann) Dettmann, Deltoidospora cf. australis, (Couper) Pocock, Verrucosisporites sp. 1, Verrucosisporites sp. 2 son nuevas formas para la Formación Río Turbio. La especie Crassoretitriletes vanraadshooveni Germeraad et al. es un nuevo registro para Argentina y Gleicheniidites circinidites Dettmann lo es para el Eoceno de Argentina.
de Argentina.
Andrés F. Herrera-Flórez, Florian Braig, Carolin Haug
et al.
Neuroptera is one of the smaller ingroups of Holometabola, the ingroup of Insecta characterised by “complete” metamorphosis. Neuroptera comprises about 6000 species in the modern fauna, but appears to have been more diverse in the past. While adults distantly resemble certain moths or damselflies, the larval forms of Neuroptera are mostly fierce predators with prominent venom-injecting stylets. The most well-known of these larvae are probably those of antlions. Antlions and their closer relatives (silky lacewings, split-footed lacewings, ribbon-winged lacewings, spoon-winged lacewings, and owlflies) form a distinct monophyletic ingroup of Neuroptera, Myrmeleontiformia, hence the antlion-like forms. The fossil record of antlion-like larvae dates back far into the Cretaceous; many forms are known by exceptionally wellpreserved specimens entrapped in amber. The oldest fossil record of a neuropteran larva (not an antlion-like form) comes from Lebanese amber. Interestingly, the supposedly oldest record of an antlion-like larva is preserved in rock and comes from the famous Lower Cretaceous Crato Formation. We re-evaluate this fossil based on high-resolution composite photography. Due to the non-availability of many key characters, standard procedures for identifying the specimen to a more narrow ingroup remains challenging. Therefore, we used a morphometric approach. A combination of non-metric multidimensional scaling (NMDS), parallel coordinate plots and discriminant function analysis indicates that the fossil is a representative of the group Ascalaphidae (owlflies) + Myrmeleontidae (antlions). We discuss implications of this result for the fossil record of neuropteran larvae. These include the rather derived morphology of the oldest fossil larva of Myrmeleontiformia in contrast to previous expectations. Furthermore, fossils from soil dwellers can not only be expected to be found in amber, but also as compression fossils.
In the last years, a murine identified as Paraethomys aff. abaigari has been repeatedly recognized in several early Pliocene localities of the Iberian Peninsula. We have revised these occurrences, as well as other samples of similar morphology, and propose that all these records correspond to a new species. We diagnose Paraethomys baeticus sp. nov. based on a large sample from the early Ruscinian site of Baza-1 (Guadix-Baza Basin, Spain). It is a medium-sized representative of the genus, with relatively well-developed longitudinal connections both in upper and lower molars, but incomplete stephanodonty. M1 displays high tubercles t6–t9 and low t4–t8 connections. M1 and, to a lesser extent, M2 have posterior spurs on t1 and t3. The t9 and t12 are absent in M2. In m1, a round islet of enamel between the anteroconid and the protoconid-metaconid is regularly observed, as well as a general lack of medial anteroconid, moderate labial cingulum with large posterior accessory cuspid, and longitudinal spur. The new species differs from other European representatives of the genus Paraethomys mainly in its size, which is intermediate between that of the small-sized Paraethomys meini and the large-sized Paraethomys abaigari. In addition, both the size and relative width are smaller than those of Paraethomys jaegeri. The frequency of posterior spurs on t1 and t3 of M1 and M2 is higher than that of P. meini and lower than that of P. jaegeri. The new species here described represents a key biochronological and biostratigraphic marker, since it is restricted to levels of late early Ruscinian age. Thus, this species is useful for establishing divisions within the early Ruscinian, and becomes a characteristic taxon for the early Pliocene in the terrestrial record of the Iberian Peninsula. Magnetobiostratigraphic correlations suggest a chronological range for P. baeticus sp. nov. between ca. 4.6 and 4.3 Ma.
The first detailed geological and paleontological survey of the Santa Cruz Formation (Early–Middle Miocene; Burdigalian–early Langhian) along the Río Santa Cruz was carried out in 1887 by Carlos Ameghino, who recovered more than 2000 fossil remains. In that same year, his brother Florentino studied and reported these remains, recognizing 122 taxa, of which 110 were new species. Fourteen of these new species were of sloths (Xenarthra, Folivora). In this contribution we report and describe new fossil sloth remains recovered in recent expeditions (between 2013 and 2014) along the southern banks of the Río Santa Cruz. The new specimens were recovered from two localities: Barrancas Blancas and Segundas Barrancas Blancas. We review the taxonomic richness of fossil sloths, in comparison with other Santacrucian localities recently studied, e.g, from the Atlantic coast and from the Andean region. An analysis of the original taxa erected by Ameghino is also included. As several of the original fossils on which these taxa are based are no longer available, we explore the value of the new collection in helping resolve systematic issues, as well as considering the specimens that formed the basis for the species erected by Ameghino in 1887. Further, the degree to which W.B. Scott’s systematic decisions on the Santacrucian sloths, published in 1903 and 1904, should continue to be recognized is also assessed.
Andrea Arcucci, Elena Previtera, Adriana C. Mancuso
Proterochampsians are a South American endemic group of non-archosaurian archosauriforms with morphological characteristics recollecting Recent crocodilians, and therefore have been proposed as aquatic species. However, this has not been based on careful examination of anatomical and histological features. We provide a review of the morphological and histological evidence present in the skeleton of proterochampsids and discuss its implications for inferring the lifestyles of these organisms. Anatomical features such as a secondary palate, marginal dentition, palatine teeth, morphology of the tail, limb modification, and dermal armor are reviewed, and details of histological structures are described based on bone thin sections. Histological examination reveals a predominance of fibrolamellar bone tissue, suggesting rapid periosteal osteogenesis and therefore overall fast bone growth. The existence of discontinuities (LAGs) demonstrates that these animals responded to changes in their environment. Ecomorphological features do not provide definitive evidence for the lifestyles of proterochampsids, but allow us to propose a terrestrial/amphibious condition. The same is true of the histological features, particularly compactness of the bone.
We here present a new hyaenodont genus and species from the Lutetian locality of Egerkingen γ (Switzerland; MP13?): Cartierodon egerkingensis gen. et sp. nov. The new taxon is represented by numerous dental elements, mostly isolated teeth. The molars show typical features of a hypercarnivorous predator such as the strong reduction of the crushing (talonid/protocone) and puncturing (metaconid) structures. The calculation of several dental indices indicates that this hyaenodont may have been a bone-cracking predator. The new taxon differs from all the hyaenodonts previously known in Europe during the Ypresian and Lutetian by its larger size, with an estimated mass of almost 29 kg (the size of the extant African wild dog, Lycaon pictus). Other hyaenodonts known for this period do not exceed 20 kg. Previous authors proposed the hypothesis of an ecological limitation of the body mass, but the description of Cartierodon egerkingensis indicates instead that the European hyaenodonts continuously increased in size throughout the Eocene. We also performed a phylogenetic analysis in order to test the relationships of this new taxon: the new hyaenodont appears to be closely related to the Lutetian hyaenodont Prodissopsalis eocaenicus.
Two of the best known Mesozoic marine reptile assemblages can be found in units deposited in the Jurassic Sub-Boreal Seaway of the UK: the late Middle Jurassic Oxford Clay Formation (OCF) and Late Jurassic Kimmeridge Clay Formation (KCF). They record two very differently structured faunas, but understanding the turnover between them is hampered by a gap in the fossil record that spans much of the Oxfordian, the so-called “Corallian gap”. We provide a comprehensive review of specimens from the Corallian Group (CG) of the UK, which includes the first descriptions of several fossils, particularly teeth. We demonstrate that there is a severe reduction in observed marine reptile diversity during the Oxfordian, with several Callovian taxa well known from the OCF not persisting into the Corallian strata, including small-to-mid-sized pliosaurids and longirostrine teleosaurids. We do, however, find evidence that at least one member of each key OCF lineage (plesiosauroids, pliosaurids, ichthyosaurs, and thalattosuchians) survived into the Corallian interval, and that one keystone KCF lineage (the Torvoneustes line of metriorhynchid thalattosuchians) was present during this time, indicating an earlier radiation of this group than previously thought. We suggest that faunal turnover between the OCF and KCF may have been driven by environmental perturbations during the Oxfordian, which selectively removed small bodied pliosaurids and longirostrine teleosaurids from the Jurassic Sub-Boreal Seaway, but less affected metriorhynchids, plesiosauroids, and ophthalmosaurid ichthyosaurs. The preferential removal of taxa from the sub-Boreal realm may have helped facilitate the radiation of lineages that became dominant during the Late Jurassic.