A new extinct genus of Glandulariini with two species from Upper Cretaceous Burmese amber (Coleoptera: Staphylinidae: Scydmaeninae)

The Glandulariini (=Cyrtoscydmini) is today the largest, most species-rich and most diverse tribe of Scydmaeninae comprising over 70% of the extant species of this subfamily. Named genera and species of Glandulariini are known mostly from Miocene to Eocene ambers, with only one, recently described Mesozoic taxon. Here we report the second genus of Glandulariini from Upper Cretaceous Burmese amber, Cenomaniola Jałoszyński and Yamamoto, gen. nov., with two species, C. carinata Jałoszyński and Yamamoto, sp. nov. and C. macrophthalma Jałoszyński and Yamamoto, sp. nov. Cenomaniola shows the general body plan typical of the ‘Euconnus complex’ within Glandulariini, with thick bristles on the sides of head and pronotum, a character conserved for nearly a hundred million years. With the previous discovery of Scydmobisetia Jałoszyński and Yamamoto, two major body forms typical of the extant Glandulariini are already proved to have differentiated in or before the Late Cretaceous. This demonstrates early origins and a long conservation of ‘Euconnus-like’ and ‘Sciacharis/Horaeomorphus-like’ body plan in the currently largest group among Scydmaeninae.     

Clidicostigus gen. nov., the first Mesozoic genus of Mastigini (Coleoptera: Staphylinidae: Scydmaeninae) from Cenomanian Burmese amber

The Mastigitae is a small supertribe of ant-like stone beetles that currently includes nine extant and five extinct genera. Extinct taxa are known within tribes Clidicini and Mastigini; the latter with one genus discovered in Baltic amber. For the first time, a Mesozoic genus of the tribe Mastigini is described, Clidicostigus arachnipes Jałoszyński, Brunke and Bai, gen. et sp. nov., from Cenomanian Burmese amber. The new taxon shares an enlarged and spiny scape and pedicel with its extant relatives but has deep elytral grooves and a strongly elongate and asymmetrical maxillary palpomere IV; the beetle has also enormously elongate maxillary palps and legs. The elongation of appendages in combination with only moderately large eyes is postulated to have evolved as an adaptation to running quickly, with tactile and chemical senses predominating over sight. The mode of life of Clidicostigus might have been similar to that of extant Mastigini, especially of particularly slender South African species that run on the ground and climb bushes and trees in search of prey.     

The extant genus Eutheia (Coleoptera: Staphylinidae: Scydmaeninae) discovered in Upper Cretaceous Taimyr amber

The Eutheiini includes over 90 extant species classified in seven genera and distributed predominantly in the Northern Hemisphere. So far only one extinct genus and species unambiguously placed in this tribe has been known, Archeutheia, from Albian of Spain. We report the discovery of Eutheia, a member of the largest extant genus of Eutheiini, in Santonian of northern Siberia. Extant species of Eutheia are primarily defined on the basis of male genital characters, and the specimen discovered in Taimyr amber is a female; consequently it is described as Eutheia sp. The new finding remarkably extends the known range of Eutheiini during Cretaceous over the area of about 6 thousand kilometers, from the Iberian Plate to northern Siberia. A long morphological stasis in Eutheia suggests that this genus was associated with stable mesic microhabitats of the upper soil layers or rotten wood for at least 83 my.     

Cretaceous amber inclusions of Spain and Myanmar demonstrate early diversification and wide dispersal of Cephenniitae (Coleoptera: Staphylinidae: Scydmaeninae)

The taxonomic status of previously misplaced species of an ant-like stone beetle from Spanish amber (Albian) is clarified. Specimens of Kachinus magnificus (originally placed as incertae sedis within Scydmaenitae) were re-examined and their characters were found different from those of the type species of Kachinus from Myanmar amber. Consequently, Archeutheia gen. nov. is proposed to accommodate the Spanish species, resulting in Archeutheia magnifica comb. nov. Moreover, in a comprehensive phylogenetic analysis Archeutheia was placed as a sister group to extant Eutheia, within the tribe Eutheiini of Cephenniitae. A specimen of an undetermined genus from Myanmar amber clearly belonging in Cephenniini is also recorded. Both taxa represent the first definite Cretaceous Cephenniitae, a supertribe whose recent members are distributed on all continents but are especially diverse in the Oriental and East Palaearctic regions. This finding demonstrates a diversification of two presently most species-rich tribes of Cephenniitae already in Early Cretaceous. Archeutheia is strikingly similar to the extant species of Eutheia and Veraphis, showing male dimorphic characters (modified protrochanters) and antennal cavities characteristic of Palaearctic Eutheiini. This fact suggests a long morphological stability in the supertribe. A previously proposed hypothesis of an early presence of the Cephenniitae in the Northern Hemisphere is for the first time supported by the fossil record, and the palaeolocalities (western Europe and Southeast Asia) demonstrate a wide distribution of Cephenniitae in the Cretaceous and an early split of its ancestral lineage.     

A densely feathered ornithomimid (Dinosauria: Theropoda) from the Upper Cretaceous Dinosaur Park Formation,Alberta, Canada

A recently discovered articulated partial skeleton of Ornithomimus from the Upper Cretaceous Dinosaur Park Formation of Alberta, Canada is remarkable in the extent and quality of preservation of integumentary structures including feathers. It is the first ornithomimid to preserve a tail bearing extensive plumaceous feathers that are slightly more elongate in comparison to those present on the remainder of the body. However, the underside of the tail and the hind limb distal to the middle of the femur appear devoid of plumage. Overall, the plumage pattern in Ornithomimus is similar to that of Struthio camelus (ostrich) and other large palaeognaths, indicating a probable function in thermoregulation. The specimen also preserves the body outline around the legs, including a skin contour anterior to the femur, analogous to skin webs in extant birds. Whereas the knee web of birds bridges the knee to the abdomen, in Ornithomimus it spans from the mid-femoral shaft to the abdomen, and is herein referred to as an anterior femoral web. This is the first report of such soft tissue structures in non-avian theropods. It may indicate that the resting position of the femur was positioned more anteroventrally in ornithomimids than in most theropods, and in that sense may have been transitional to the situation in modern birds.     

A new tribe,new genus,and new species of Mordellidae (Coleoptera: Tenebrionoidea) from the Early Cretaceous amber of Spain

The new tribe Mediumiugamiini (Coleoptera: Polyphaga: Tenebrionoidea: Mordellidae) is described based on Mediumiuga sinespinis gen. et sp. nov. It is a fossil beetle from Albian (Early Cretaceous) amber from the Peñacerrada I outcrop (Spain). It is the first Spanish beetle described in amber. The mesotibiae and mesotarsi bearing multiple dorsal–lateral ridges, running oblique, metatibiae without any dorsal or dorsal–lateral ridge, only showing a subapical ridge, and metatibiae without apical spurs, define the new tribe. A key for worldwide tribes of Mordellinae, including Mediumiugamiini, is provided. Evolution of some characters of Mordellidae along Cretaceous is discussed.     

A ceratopsian dinosaur from the Late Cretaceous of eastern North America,and implications for dinosaur biogeography

Tyrannosaurs and hadrosaurs from the Late Cretaceous of eastern North America (Appalachia) are distinct from those found in western North America (Laramidia), suggesting that eastern North America was isolated during the Late Cretaceous. However, the Late Cretaceous fauna of Appalachia remains poorly known. Here, a partial maxilla from the Campanian Tar Heel Formation (Black Creek Group) of North Carolina is shown to represent the first ceratopsian from the Late Cretaceous of eastern North America. The specimen has short alveolar slots, a ventrally projected toothrow, a long dentigerous process overlapped by the ectopterygoid, and a toothrow that curves laterally, a combination of characters unique to the Leptoceratopsidae. The maxilla has a uniquely long, slender and downcurved posterior dentigerous process, suggesting a specialized feeding strategy. The presence of a highly specialized ceratopsian in eastern North America supports the hypothesis that Appalachia underwent an extended period of isolation during the Late Cretaceous, leading the evolution of a distinct dinosaur fauna dominated by basal tyrannosauroids, basal hadrosaurs, ornithimimosaurs, nodosaurs, and leptoceratopsids. Appalachian vertebrate communities are most similar to those of Laramidia. However some taxa-including leptoceratopsids-are also shared with western Europe, raising the possibility of a Late Cretaceous dispersal route connecting Appalachia and Europe.     

The structural preservation of a titanosaurid (Dinosauria: Sauropoda) vertebral ligament

Within the past decade exceptional preservation of original organic components have been reported from several dinosaurian families, including members of Sauropodomorpha. Here we document the partial preservation of a vertebral ligament in the dorsal and sacral series of a titanosaur. Unlike other cases of tissue preservation, this structure does not represent biomineralization of the original organic components. Histology, morphology, and comparative anatomy from extant taxa as well as the preferential placement on the vertebral column suggests that it represents the partial preservation of the nuchal ligament. While preservation of other sauropod connective tissues are known, this case represents the first reported non-biomineralized tissue from a sauropod. In consideration of the location and external and internal morphologies compared to modern vertebral ligaments, we believe this structure to be the micritic replacement of the original tissue via microbially-mediated processes. Along with the suggestive external morphology, internally we interpret some of the unusual structures to represent the remnants of the collagen and elastin fascicles that are strongly overprinted by a clotted, thrombolytic-like fabric recording microbial activity and deposition of micrite prior to lithification. In consideration of the interpreted depositional history, we theorize that post-deposition, bacteria deposited the micrite as a byproduct of metabolization. Subsequently, the recognition of this structure as a vertebral ligament, the largest of such thus documented, substantiates previous findings on the morphological attributes of sauropod vertebral ligaments.     

Cretoleptochromus archaicus gen. et sp. nov., a new genus of ant-like stone beetles in Upper Cretaceous Burmese amber (Coleoptera,Staphylinidae, Scydmaeninae)

A new genus and species of the ant-like stone beetle supertribe Mastigitae, Cretoleptochromus archaicus gen. et sp. nov., is described and figured based on an exceptionally well-preserved individual in the Upper Cretaceous (lowermost Cenomanian, ca. 99 Ma) amber from Myanmar. Cretoleptochromus is undoubtedly placed in Mastigitae based on its distinctly geniculate antennae with strongly elongate antennal scape, and pointed labial palpomere III. Cretoleptochromus is most likely the sister taxon to the extinct Palaeoleptochromus O'Keefe from the Late Cretaceous Canadian amber. Cretoleptochromus shares with Clidicini the distinct posterior collar of pronotum; with Leptomastacini the presence of mesocoxal lateroventral bristles. The new discovery may help to elucidate the relationships among the Recent three tribes, particularly for Leptomastacini and Clidicini.     

Effectiveness of various dispersed alkaline substrates for the pre-treatment of ferriferous acid mine drainage

Dispersed alkaline substrates (DAS) have been successfully used in passive treatment of highly contaminated acid mine drainage (AMD) to limit coating and clogging issues. However, further optimization of DAS systems is still needed, especially for their long-term efficiency during the treatment of ferriferous AMD. In the present study, three types of DAS comprised of natural alkaline materials (wood ash, calcite, dolomite), in different proportions (20%v/v, 50%v/v, 80%v/v), and a substrate with high surface area (wood chips) were tested in 9 batch reactors. The testing was carried out, in duplicate, for a period of 91 days, to evaluate the comparative performance of the mixtures for iron pre-treatment in ferriferous AMD (2500 mg/L Fe, at pH 4). Results showed increasing of pH (between 4.15 and 7.12), regardless of the proportion of alkaline materials in the DAS mixtures. Among the tested mixtures, wood ash type DAS were more effective for Fe removal (99.9%) than calcite or dolomite type DAS (up to 66%). All tested DAS had limited efficiency for sulfate removal and an additional treatment unit, such as a sulfate-reducing biochemical reactor, is needed. Moreover, due to the similar performances of the calcite and dolomite DAS, they could be potentially substituted and rather be used in a polishing treatment unit. Based on these findings, the most promising mixture was the 50% wood ash type DAS (WA50-DAS).     

The youngest record of metriorhynchid crocodylomorphs,with implications for the extinction of Thalattosuchia

Here we describe an isolated tooth of a metriorhynchid crocodylomorph from the Hybla Formation (Aptian, Lower Cretaceous) of Rocca Chi Parra quarry (Montagna Grande, Calatafimi, Trapani Province), Sicily, Italy. The specimen shares with the Upper Jurassic taxon Plesiosuchus manselii a mediolaterally compressed conical tooth crown, noticeable lingual curvature, mesial and distal carinae with microscopic, rectangular contiguous denticles, strong distal curvature of the mesial margin, and the presence of weak 'carinal flanges' on the labial and lingual surfaces (which are preeminent at the mid-crown). This suite of morphologies is also present in an unnamed Valanginian (Lower Cretaceous) plesiosuchinan from France. However, the Sicilian tooth differs from these taxa in having more pronounced carinae, and faint apicobasally aligned enamel ridges. It also differs from P. manselii in having more extensive 'carinal flanges' on the labial surface. The specimen extends the known geological range of Metriorhynchidae and Thalattosuchia by approximately 7–8 million years. This overturns previous hypotheses of Metriorhynchidae becoming extinct early in the Early Cretaceous.     

The East Side Story – The Transylvanian latest Cretaceous continental vertebrate record and its implications for understanding Cretaceous–Paleogene boundary events

The latest Cretaceous continental vertebrate faunas of the wider Transylvanian area figured prominently in discussions concerning the Cretaceous–Paleogene Boundary (K-Pg) events when they were first described by Nopcsa between 1897 and 1929, because they were assumed to be late Maastrichtian in age. Subsequently their age was reconsidered as early Maastrichtian, and were thus regarded of lesser importance in understanding the K-Pg boundary events in Europe and worldwide. Moreover, Transylvanian continental vertebrate assemblages (the so-called ‘Haţeg Island’ faunas) were often lumped together as a temporally restricted assemblage with a homogenous taxonomic composition. Recent fossil discoveries and more precise dating techniques have considerably expanded knowledge of the Transylvanian vertebrate assemblages, their ages, and their evolution. A synthesis of the available stratigraphic data allows development of the first comprehensive chronostratigraphic framework of the latest Cretaceous Transylvanian vertebrates. According to these new data, expansion of continental habitats and emergence of their vertebrate faunas started locally during the latter part of the late Campanian, and these faunas continued up to the second half of the Maastrichtian. During this time, long-term faunal stasis appears to have characterized the Transylvanian vertebrate assemblages, which is different from the striking turnovers recorded in western Europe during the same time interval. This suggests that there was no single ‘Europe-wide’ pattern of latest Cretaceous continental vertebrate evolution. Together, the available data shows that dinosaurs and other vertebrates were relatively abundant and diverse until at least ca. 1 million years before the K-Pg boundary, and is therefore consistent with the hypothesis of a sudden extinction, although this must be tested with future discoveries and better age constraints and correlations.     

Emplacement of the La Peña alkaline igneous complex,Mendoza, Argentina (33° S): Implications for the early Miocene tectonic regime in the retroarc of the Andes

The La Peña alkaline complex (LPC) of Miocene age (18–19 Ma) lies on the eastern front of the Precordillera (32°41ʹ34ʺS, 68°59ʹ48″W, 1400–2900 m a.s.l.), 30 km northwest of Mendoza city, Argentina. It is a subcircular massif of 19 km² and 5 km in diameter, intruded in the metasedimentary sequence of the Villavicencio Formation of Silurian-Devonian age. It is the result of integration of multiple pulses derived from one or more deep magma chambers, which form a suite of silicate rocks grouped into: a clinopyroxenite body, a central syenite facies with a large breccia zone at the contact with the clinopyroxenite, bodies of malignite, trachyte and syenite porphyry necks, and a system of radial and annular dikes of different compositions. Its subcircular geometry and dike system distribution are frequent features of intraplate plutons or plutons emplaced in post-orogenic settings. These morphostructural features characterize numerous alkaline complexes worldwide and denote the importance of magmatic pressures that cause doming with radial and annular fracturing, in a brittle country rock. However, in the LPC, the attitude of the internal fabric of plutonic and subvolcanic units and the preferential layout of dikes match the NW–SE extensional fractures widely distributed in the host rock. This feature indicates a strong tectonic control linked to the structure that facilitate space for emplacement, corresponding to the brittle shear zone parallel to the N–S stratigraphy of the country rock. Shearing produced a system of discontinuities, with a K fractal fracture pattern, given by the combination of Riedel (R), anti-Riedel (R′), (P) and extensional (T) fracture systems, responsible for the control of melt migration by the opening of various fracture branches, but particularly through the NW–SE (T) fractures. Five different pulses would have ascent, (1) an initial one from which cumulate clinopyroxenite was formed, (2) a phase of mafic composition represented by dikes cross-cutting the clinopyroxenite, (3) a malignite facies that causes a small breccia in the clinopyroxenite, (4) a central syenite facies that develops breccias at the contact with the clinopyroxenite and, finally, (5) porphyry necks and a system of radial dikes intruding all units. At the moment of the emplacement different mechanisms would have acted, they summarized in: 1) opening of discontinuities synchronous to the magma circulation as the principal mechanism for formation of dikes and conduits; 2) stoping processes, that play an important role in the development of the breccia zone and enabling an efficient transference of material during the emplacement of the syenitic magma and 3) shear-related deformation (regional stress), affected the internal fabric of the facies, causing intracrystalline deformation and submagmatic flow, which is very evident in the central syenite intrusive. The kinematic analysis of shear planes allows proposing that emplacement of the LPC took place in a transtensive regime, which would have occurred in the back-arc of the Andes orogen, during a long period spanning from Miocene to the present, of the compressive deformation responsible, westward and at the same latitude, for the development of the Aconcagua fold and thrust belt.     

The oldest tachyporine rove beetle in amber (Coleoptera,Staphylinidae): A new genus and species from Upper Cretaceous Burmese amber

A new genus and species of extinct rove beetle, Procileoporus burmiticus gen. and sp. n., is described from Upper Cretaceous Burmese amber (Cenomanian; ca. 99 Ma). Due to the condition of the fossil, parts of the body could not be examined, but sufficient characteristics were visible to allow the specimen to be placed within the subfamily Tachyporinae (tribe Tachyporini). Procileoporus is most similar to the extant genus Cileoporus Campbell in having a slender abdomen, but it differs in having much shorter abdominal setae, prominent striated microreticulation on the elytra, non-lobed tergite VIII, and in other details of the male genital segments. This is the first tachyporine rove beetle from Burmese amber and the oldest record of the subfamily in amber. The evolution of sexual dimorphism in the genital segments is briefly discussed.     

The persistence and role of basin structures on the 3D architecture of the Marañón Fold-Thrust Belt,Peru

The 3D architecture of fold-thrust belts commonly involves thin-skinned and thick-skinned deformation. Both thick- and thin-skinned deformation styles have been suggested to occur in the Marañón Fold-Thrust Belt (MFTB) in Peru, but the relative timing and strain partitioning associated with them are not well understood. We demonstrate that inherited basement structures along the Peruvian convergent margin reactivated during the evolution of the MFTB. We present results from field mapping, interpretation of remote sensing imagery, and cross section construction and restoration. The results show that the Chonta Fault, a median pre-folding basin normal fault, was inverted and acted as a mechanical buttress during initial east-vergent contraction of the fold-thrust belt. This fault separates the belt into two domains of distinctly different structural styles. During the Eocene, units to the west of the Chonta Fault deformed by folding, using the fault as a buttress, and subsequently propagated eastward by thin-skinned thrusting. This was followed in the Miocene by west-vergent, basement-involved deformation, which overprinted the earlier east-vergent, thin-skinned structures. The proposed tectonic model of the MFTB highlights the role of basement-fault reactivation during orogenesis and the involvement of deep structures in partitioning deformation styles.     

A simple procedure to simulate a smooth elastic-plastic transition in Cam-Clay models

A simple procedure is proposed to simulate a smooth transition from elastic to elastoplastic behaviour in Cam-Clay models. The procedure consists of the definition of an external constitutive surface where full yield is assumed, and an internal one that allows the definition of the position in which plastic strains start to appear before the external yield surface is reached. The comparison of the model results with different laboratory tests shows the validity of the procedure. The method considers one additional parameter with regard to a “standard” critical state model, and it can easily be implemented in existing integration modules.     

The first fossil of dasycerine rove beetle (Coleoptera: Staphylinidae) from Upper Cretaceous Burmese amber: Phylogenetic implications for the omaliine group subfamilies

The enigmatic staphylinid subfamily Dasycerinae consists of only 17 species within a single extant genus Dasycerus, but it is easily distinguished from other rove beetles by overall, latridiid beetle-like body and extremely slender, verticillate antennae. Direct fossil evidence is lacking for this group. Here, I describe the first fossil of this peculiar subfamily, Protodasycerus aenigmaticus gen. and sp. n., from the Upper Cretaceous Burmese amber. Despite considerable external similarities to extant dasycerine species, this new genus possesses several important morphological differences: a much smaller body size (ca. 1.1 mm), narrowly elongate antennomeres 1 and 2, not strongly transverse metaventrite, elytra striate but not tricostate, and truncate posterior margin of the elytra exposing four abdominal tergites dorsally. The new finding of a Cretaceous representative of the Dasycerinae helps elucidate the origin and early evolution of the omaliine group subfamilies, implying rather close similarities between the Dasycerinae and the monobasic subfamily Neophoninae. Discovery of P. aenigmaticus suggests a rather ancient origin of the subfamily by the Upper Cretaceous.     

The first fossil Megalopsidiinae (Coleoptera: Staphylinidae) from Upper Cretaceous Burmese amber and its potential for understanding basal relationships of rove beetles

The first definitive fossil of the peculiar monotypic rove beetle subfamily Megalopsidiinae is described as a new species Megalopinus extinctus sp. n. It represents a stem lineage valuable for the study of the early diversification of Staphylinidae, where sister group relationships of Megalopsidiinae currently remain a big controversy. This discovery corroborates the Mesozoic origin of this subfamily implied by its presumably basal phylogenetic position within Staphylinidae and hitherto available fossil record for the family. Well preserved peculiar mouthparts of M. extinctus specialized similarly with recent Megalopinus suggest the same mode of feeding in Megalopsidiinae for nearly a hundred million years.     

Invertebrate traces in pseudo–coprolites from the upper Cretaceous Marília Formation (Bauru Group), Minas Gerais State,Brazil

Pseudo–coprolites are inorganic structures often confused with fossil faeces. The absence of some diagnostic features, such as inclusions, coprofabrics, grain adhesion, and defined shape, suffices to disregard these structures as coprolites. Herein we revise the so–called “coprolites” from the Serra da Galga Member of the Marília Formation (Maastrichtian of Bauru Group, Paraná Basin), at “Ponto 1 do Price” locality near the town of Peirópolis (Uberaba municipality, Minas Gerais State, Brazil) and conclude that they are, in fact, pseudo–coprolites related to calcretes. These data also agree with the geological setting of “Ponto 1 do Price”, composed mainly of coarse sandstones and conglomerates, in which these pseudo–coprolites were found. In addition, some of these specimens exhibit superficial traces, here described as a new boring ichnospecies, Asthenopodichnium fallax isp. nov., produced by invertebrates in Late Cretaceous fresh–water settings of Brazil.