Saurischian (theropod–sauropod) track assemblages from the Jiaguan Formation in the Sichuan Basin,Southwest China: ichnology and indications to differential track preservation

Saurischian (theropod and sauropod) tracks and trackways from the Jiaguan Formation (Lower Cretaceous) of the Sichuan Basin are exposed as natural casts with associated undertrack or transmitted print casts. The theropod tracks (cf. Eubrontes and Grallator) were left by differently sized trackmakers. This is a further example for the occurrence of characteristic Lower Jurassic ichnotaxa in the Cretaceous that obviously had a more extended stratigraphic range in East Asia. The sauropod trackway is tentatively assigned to cf. Brontopodus based on imprint morphology and (nearly wide) gauge. The tracks, however, allow a detailed study of their formation and the taphonomic processes under different substrate conditions. Differential preservation and erosion of primary sedimentary structures, and post-burial deformation structures, give insight into a complex preservational history during a low energy phase interrupting the deposition of a sequence of thick high energy sandstones. This is the sixth report of dinosaur tracks from the Jiaguan Formation and the fifteenth report from the Lower Cretaceous of Sichuan Province. Thus, the tetrapod ichnological record in this region is rapidly becoming of major importance for our knowledge of dinosaur faunas in south-western China.     

A tetrapod footprint assemblage with possible swim traces from the Jurassic–Cretaceous boundary,Anning Formation,Konglongshan, Yunnan,China

A small tetrapod footprint assemblage from the Anning Formation (Upper Jurassic–Lower Cretaceous) at Konglongshan Town, Yunnan Province, China, contains possible swim traces attributable to theropod dinosaurs based on their tridactyl and mesaxonic pes morphology. Morphotypes are tentatively assigned to the ichnogenera Characichnos and Wintonopus, a third one is similar to Hatcherichnus. Due to the inherent variability observed in tetrapod swim tracks, the names are used here informally describing footprints that reflect a distinct trackmaker behavior rather than anatomically accurate images of the pes anatomy. Variation of the imprint shape is obviously due to extramorphological effects and does not indicate taxonomic diversity of trackmakers. Elongate, slender impressions associated with these tracks are discussed here as possible tail traces. Trackmakers were possibly buoyant and active swimming individuals touching and scratching the bottom of deeper waterbodies with the distal ends of their digits. The orientation of the traces perpendicular to preserved ripples suggest cross-current movement and activities.     

Two new theropod egg sites from the Late Jurassic Lourinhã Formation,Portugal

Two new Late Jurassic (uppermost Late Kimmeridgian) dinosaur eggshell sites are described, Casal da Rola and Porto das Barcas, both near Lourinhã, central-west Portugal. Casal da Rola yields eggshells with an obliquiprismatic morphotype comparable to those from a nest with the associated fossil embryos from Paimogo, tentatively assigned to the theropod Lourinhanosaurus antunesi. The Porto das Barcas eggshells have a dendrospherulitic morphotype with a prolatocanaliculate pore system. This morphotype was also recognised in eggshells from a clutch with associated Torvosaurus embryos at the Porto das Barcas locality. A preliminary cladistic analysis of eggshell morphology suggests theropod affinities for the Casal da Rola eggs, but is unable to resolve the phylogenetic position of the Porto das Barcas eggs. The eggshells at both sites are preserved in distal flood plain mudstones and siltstones. Carbonate concretions within the deposits indicate paleosol development.     

Theropod and possible ornithopod track assemblages from the Jurassic–Cretaceous boundary Houcheng Formation,Shangyi, northern Hebei,China

Dinosaur track assemblages from the Houcheng Formation in the small continental Shangyi Basin of northern Hebei Province, China bridge a gap in the record of vertebrates from this unit and enrich our knowledge of ichnofaunas from the Jurassic–Cretaceous boundary. Their stratigraphic position between the Middle Jurassic Yan-Liao Biota and the Lower Cretaceous Jehol Biota gives them a special importance. New discoveries allow a re-assessment of theropod and possible ornithopod tracks that are present with several trackways. Seventy-three footprints were examined and documented. Despite their smaller size, the tridactyl mesaxonic theropod tracks show morphological similarities with the ichnogenus Therangospodus known from the Upper Jurassic deposits of North America, Europe, and Central Asia. The possible ornithopod tracks lack an associated manus imprint, suggesting a bipedal trackmaker. These possible ornithopod tracks from the Houcheng Formation provide evidence for the presence of small basal ornithopods or basal Cerapoda in the Upper Jurassic–Lower Cretaceous in this region. The depositional environment was the margin of an extensive shallow lake with fluctuating water levels under seasonally dry climate.     

Darriwilian–Sandbian (Middle–Late Ordovician) shallow warm-water deposits in the Upper Yangtze region,South China: A case study from the Qiaojia area,northeastern Yunnan Province

The Middle–Late Ordovician Nuoduo and Huadan formations are well exposed at Songliang of northeastern Yunnan Province, representing rare neritic carbonate sediments deposited in the Yangtze region, South China during that time. Detailed sedimentological analyses support the recognition of ten microfacies from the succession, including shale (MF 1), argillaceous mudstone/dolostone (MF 2), mollusk-ostracod wacke-packstone (MF 3), peloidal wacke- to pack-grainstone/dolostone (MF 4), ooid-cortoid-peloid pack-grainstone/dolostone (MF 5), peloidal bindstone (MF 6), bioclastic wacke-packstone (MF 7), green algae mud-wackestone to floatstone (MF 8), bioclast-lithoclast float-rudstone (MF 9) and green algae bindstone (MF 10). Types A, B and C of shallowing-upward sequences are constructed according to vertical associations of MFs. The Nuoduo Formation mainly comprises Type A and Type B, both being characterized by abundant peloids, ooids, cortoids and aggregate grains. MF 5 and MF 6 cap the Type A and Type B sequences, respectively, suggesting an overall restricted marine environment shifting cyclically from lagoon to shoal, or lagoon to tidal flat, respectively. Type C sequences, occurring in the topmost Nuoduo to Huadan formations, contain various green algae indicative of open-sea, euphotic subtidal zones. The transition from A and B to C sequences is marked by ferruginous ooidal intervals, possibly correlated to relative sea-level rise and/or tectonic activities. A continuous neritic, warm-water environment is proposed for this area from late Middle to Late Ordovician, with the Nuoduo Formation filling the absence of warm-water deposits in the tropical or subtropical Yangtze region during Middle Ordovician. The increasing diversity and abundance of green algae in the Huadan Formation might represent a global radiation event of marine flora during the studied interval. Unique fossils and environments distinct from those of the interior Yangtze region are documented here, leading to a better understanding of the Ordovician System regionally and globally.     

Ostracods from the Upper Cretaceous–Paleocene Jiaozhou Formation of Jiaozhou,Shandong, China and their biostratigraphic significance

Late Mesozoic–Cenozoic non-marine deposits are well developed in the Jiaolai Basin, eastern Shandong Province, China, yielding abundant fossils including ostracods. In order to further understand the geological settings of the basin during the Late Cretaceous–Paleogene, three boreholes (JK-1, JZK-01 and JZK-02) were drilled in the city of Jiaozhou. Nine genera and sixteen species (including six indeterminate species) of ostracods are described from the Jiaozhou Formation in the three boreholes, including Cypridea, Mongolocypris, Talicypridea, Candona, Eucypris, Cyprois, Porpocypris, Sinocypris and Timiriasevia. Of these, Porpocypris sphaeroidalis Guan, 1978 is reported from northern China for the first time, indicating that this species has great potential to be an indicator of the K/Pg boundary. Correlation of these species with the known Cretaceous–Paleogene ostracod assemblages suggests that the age of the Jiaozhou Formation could be latest Cretaceous–Paleocene in borehole JK-1, Campanian–Maastrichtian in borehole JZK-01, and Maastrichtian–Danian in borehole JZK-02. The exact position of K/Pg boundary, however, is unavailable for the present in the Jiaozhou Formation from boreholes JK-1 and JZK-01.     

Middle–Late Ordovician brachiopods from Ningnan,southern Sichuan Province,Southwest China: Implications for macroevolution and palaeogeography

Middle to Late Ordovician brachiopods from the Huadan Formation (upper Darriwilian–Sandbian) of Ningnan County, southern Sichuan Province, are systematically documented here for the first time. The locality belongs to the western margin of the Upper Yangtze Platform, South China palaeoplate, and the brachiopod fauna includes one new genus and three new species as well as five other constituents: Hingganoleptaena sp., Acculina zhongliangziensis n. sp., Ningnanmena longisepta n. gen. n. sp., Kassinella (Trimurellina) minuta n. sp., Lepidorthis typicalis Wang, 1955, Protoskenidioides weixinensis Zhan and Jin, 2005, Porambonites transversus Xu, Rong and Liu, 1974, and Psilocamerella sp. Taxonomically it is a typical representative of a Middle to early Late Ordovician brachiopod fauna, and, together with some other evidence from other fossil groups like trilobites, conodonts, chitinozoans, a late Darriwilian–Sandbian age could be inferred for the horizon yielding this fauna. According to the richness of each constituent, this fauna is suggested to be called the Acculina-Ningnanmena fauna (ANF). Numerical palaeogeographical analysis shows that two broad palaeobiogeographic provinces could be recognized during this particular time interval, and, although the ANF is grouped into the South China cluster, it shares very little similarity with other representatives of that group except for two cosmopolitans. It further confirms that the Great Ordovician Biodiversification Event (GOBE), in other words the Ordovician radiation, was actually manifested by the strong localization of major marine organisms such as brachiopods, trilobites, graptolites, etc.     

Sauropod and Small Theropod Tracks from the Lower Jurassic Ziliujing Formation of Zigong City,Sichuan, China,with an Overview of Triassic–Jurassic Dinosaur Fossils and Footprints of the Sichuan Basin

A dinosaur footprint assemblage from the Lower Jurassic Ziliujing Formation of Zigong City, Sichuan, China, comprises about 300 tracks of small tridactyl theropods and large sauropods preserved as concave epireliefs (natural molds). The theropod footprints show similarities with both the ichnogenera Grallator and Jialingpus. Three different morphotypes are present, probably related to different substrate conditions and extramorphological variation. A peculiar preservational feature in a morphotype that reflects a gracile trackmaker with extremely slender digits, is the presence of a convex epirelief that occurs at the bottom of the concave digit impressions. It is possibly the result of sediment compaction underweight load when the pes penetrated the substrate, being a resistant residue during exhumation and weathering. The sauropod tracks belong to a trackway with eight imprints consisting of poorly preserved pes and manus tracks and a better preserved set, probably all undertracks. The narrow-gauge trackway pattern resembles the ichnogenus Parabrontopodus well known from the Jurassic but other features such as the minor heteropody are different. The assemblage enriches the dinosaur record from the famous Zigong locality and the evidence from the Lower Jurassic in this area that was restricted to a few skeletal remains and footprints. Furthermore it proves the presence of small theropods, whereas skeletons of the group, well- known from the Middle-Upper Jurassic of Zigong, are of medium to large size only. Remarkable is the dominance of saurischians in these assemblages, which is characteristic of Jurassic dinosaur communities whereas the Cretaceous record shows an increase of ornithopod groups. An overview of the dinosaur trace and body fossil record of the Sichuan Basin supports this view. The paleoenvironment can be designated as a low-latitude tropical freshwater lake as it is indicated by bivalve shells.     

Paleosols and host rocks from the Middle–Upper Permian reference section of the Kazan Volga region,Russia: A case study

The Urzhumian (Wordian) and Severodvinian (Capitanian) reference section of the Monastery Ravine (Kazan Volga region, Russia), contains two siltstone lithofacies: (a) laminated and (b) massive. Depositional settings of the laminated siltstones can be interpreted as perennial to ephemeral lakes; depositional settings of the massive siltstones are interpreted as floodplains with soil cover and periodical silt influx in wet seasons. The bulk geochemistry of siliciclastics has revealed a high degree of weathering of both types of siltstone. The similar chemical composition, mineralogy, and grain size suggest the same provenance of silt material. Geochemical data indicate eastern source rocks, which are the Permian red beds of the Cis-Ural plains.The main genetic types of paleosols hosted in the massive siltstones in the studied section, include moderately developed Vertisols and Calcisols with drab-colored root traces, calcareous nodules, low chroma mottles, angular blocky peds and slickensides. These pedofeatures indicate in general a semi-arid climate with clear seasonality of rainfall. Major oxides of the paleosol matrix were used to estimate paleoprecipitation through the bases to alumina (ΣBases/Al) ratio and chemical index of alteration minus potassium (CIA-K) proxies. Estimates from Urzhumian paleosols indicate relatively low mean annual precipitation (MAP) of 390 mm/yr. The transition to the Severodvinian paleosols is marked by a noticeable MAP increase up to 777 mm/yr. This climate moistening coincides with changes in the morphology of paleosols from dolomitic with low redoximorphy to calcitic with gley horizons. The pedogenic carbonate nodules consisting of dolomicrite (5–10 μm) are very common in the Urzhumian paleosols and their morphology, micromorhology and isotopic features indicate the pedogenic origin of dolomite.Sedimentological and paleopedological features of the studied siltstones, as well as the location of the Volga-Ural basin in a mid-latitude position (25–32 °N) indicate a monsoonal character of precipitation during the Middle Permian.     

U–Pb SHRIMP age for the Tuchengzi Formation,northern China,and its implications for biotic evolution during the Jurassic–Cretaceous transition

The Late Jurassic–Early Cretaceous Tuchengzi Formation is widespread in North China. Its clastic deposits indicate a tropical, dry, and hot paleoclimate, different from the subtropical, humid, and seasonal climate in the early Middle Jurassic. The sudden environmental change from the Middle to Late Jurassic resulted in a rapid disappearance of the Yanliao/Daohugou Biota, with more than 90% of the species of the Yanliao/Daohugou Biota dying out and replaced by the Early Cretaceous Jehol Biota. Eolian sandstones with large-scale cross-bedding occur within the uppermost part of the Tuchengzi Formation in North China. The sandstones are stratigraphically higher than the tuff previously dated as 139 Ma. We obtained two SHRIMP zircon U/Pb ages from the tuff beds. One sample was collected from the tuff in the basal Tuchengzi Formation in northern Hebei and the other from the tuff intercalated in the eolian cross-bedded sandstones in the uppermost Tuchengzi Formation in western Liaoning. Our results show that 154 Ma is the oldest age constraint for the Tuchengzi Formation and 137 Ma is the youngest age estimate of the formation, providing an age constraint for the transition from the Yanliao Biota to the Jehol Biota.     

Differentiation of Nitrogen and Microbial Community in the Sediments from Lake Erhai,Yunnan–Kweichow Plateau,China

Abstract

As a famous plateau lake and a place rich in biodiversity located at the Hengduan Mountains, there is little research on microbial diversity and community composition in Erhai. In this study, 770,425 16S rRNA sequences had obtained at different depth samples. The abundance‐based coverage estimates (ACE), Chao1, and Shannon indices indicated the high abundance and diversity of Erhai sediment microorganisms. And they were obviously affected by human disturbance. Gammaproteobacteria, Deltaproteobacteria, Bacteroidia, Anaerolineae, Phycisphaerae, and Methanomicrobia were dominant bacteria and existed in almost all samples. The content of total nitrogen (TN) in sediments had a significant positive correlation between Syntrophus, Deltaproteobacteria, Desulfatiglans, Oxyphotobacteria, Clostridiales, Burkholderiaceae, Geobacter, Crenothrix species richness. Desulfobacca, Syntrophus, Deltaproteobacteria, Desulfatiglans, Gammaproteobacteria, Oxyphotobacteria, and Clostridiales were positively correlated with the nitrates in sediments. And the species richness of Desulfatiglans was correlated with NO₂ ^-. The RDA analysis was shown that dbRDA1 was affected mainly by the depth of lake, while the content of TN, NO₃ ^?, NO₂ ^?, and NH₄ ⁺ had the largest effect on dbRDA2. The results indicated the great relations between the diversity and composition of microbial communities and different forms of sediment nitrogen in Erhai lake sediments.     

Elatides sandaolingensis n. sp. (Cupressaceae sensu lato) — A new fossil conifer with cones from the Middle Jurassic of Xinjiang,northwestern China

Here we describe a new conifer fossil, Elatides sandaolingensis Z.X. Wang and B.N. Sun n. sp., from the Middle Jurassic Xishanyao Formation in the Turpan-Hami Basin, Xinjiang Uygur Autonomous Region, northwestern China. The materials consist of compressions represented by well-preserved leafy shoots, pollen cones, and seed cone. Leaves are characterized by long triangular shapes, with straight apex and entire margins, and two stomatal bands on the abaxial surface. Pollen cones are terminally disposed on the ultimate leafy shoots, borne singly or in clusters. Pollen sacs are long-oval shaped, with three pollen sacs fused together. Pollen grains are spherical and have small germinal papilla and few wrinkles. The seed cone is oblong, with more than 35 helically arranged bract-scale complexes, which are characterized by long-oval shape and triangular apex. Compared with the extant nine genera of Taxodiaceous Cupressaceae in the morphology of seed cone and pollen cones, the present fossil consistently shares many characteristics with the extant genus Cunninghamia, but differs in other aspects. After being compared with the reported fossil records of the fossil plants, the current species is found to be different from any known species; thus, the present fossil is referred to as a new species of Elatides. From the similarity between the present fossil and Cunninghamia, it can be inferred that there may be a genetic relationship between these two genera. Additionally, the new species has thin cuticles and slightly sunken stomata, which can provide evidence indicating that the climate of the Turpan-Hami Basin in Middle Jurassic might have been warm and humid. By studying the geological history and geographical distribution of Elatides, it can be inferred that this genus may have originated in Switzerland, and it was migrated from Xinjiang to North and South China through the Ural Mountains.     

A bryozoan fauna from the Santa Lucia Formation (Lower–Middle Devonian) of Cantabrian Mountains,NW Spain

The Lower to Middle Devonian Santa Lucia Formation of NW Spain contains a rich and well-preserved bryozoan fauna. An assemblage containing 14 species is described from two localities in Cantabrian Mountains, Abelgas, and Paradilla. One new genus with one new species is described: Isostylus abelgasensis n. sp. n. gen. Another two new species have been found: Microcampylus minor n. sp. and Acanthoclema parvula n. sp. Additionally, the following species were identified: Cyclotrypa communis (Ulrich 1890), Fistuliphragma gracilis Ernst 2008a, Leioclema attenuatum Duncan 1939, Hemitrypa cf. tenella Barrande in Počta 1894, Fenestella aff. parallela Hall 1881, Anastomopora adnata (Hall 1883), Semicoscinium rhombicum Ulrich 1890, Quadrisemicoscinium discretum (Prantl 1932). Three species are described in open nomenclature: Trepostomata sp. indet.1 and 2, and Semicoscinium sp. The described bryozoan fauna shows connections to the Lower Devonian of Bohemia, and to the Middle Devonian of Rhenish Massif and North America.     

A new odonatan (Stenophlebiidae) from the Lower Cretaceous Sinuiju Formation of North Phyongan Province,the Democratic People’s Republic of Korea

A new fossil species, Stenophlebia ryonsangensis n. sp. (Stenophlebiidae), collected from the Lower Cretaceous non-marine Sinuiju Formation, North Phyongan Province, has the following forewing characters: preserved wing slender and longer than 47.1 mm; Cr long, with three cells below it, and well aligned with distal part of ScP; Sn shorter than Cr, one cell long; supplementary veinlet below Sn aligned with RP2 and about two cells long; base of IR1 five cells distal of base of RP2. This well preserved material is the first odonatan reported in the DPRK. Congeneric species has previously been found in the Lower Cretaceous Yixian Formation of western Liaoning Province, Northeast China, thus the new discovery of Stenophlebia ryonsangensis n. sp. may contribute to evaluating the distribution and migration of Stenophlebidae and may further indicate the close relationship of the fossil layer with the famous Jehol Biota in Northeast China.     

A new genus and species of fossil scorpion (?Euscorpiidae) from the Early–Middle Eocene of Pesciara (Bolca,Italy)

Fossil scorpions are among the oldest terrestrial arthropods known from the fossil record. They have a worldwide distribution and a rich fossil record, especially for the Paleozoic. Fossil scorpions from Mesozoic and Cenozoic deposits are usually rare (except in amber-deposits). Here, we describe the only fossil scorpion from the Early to Middle Eocene Pesciara Lagerstätte in Italy. Eoeuscorpius ceratoi gen. et sp. nov. is probably a genus and species within the family Euscorpiidae. This may be the first fossil record of the Euscorpiidae, which are so far only known from four extant genera. Eoeuscorpius ceratoi gen. et sp. nov. was found in the “Lower Part” of the Pesciara Limestone, which is actually dated Late Ypresian stage (between 49.5 and 49.7 Ma). Besides a possible pseudoscorpion, the here-described fossil scorpion is the second arachnid species known from the Bolca Locality.     

Organic-walled dinoflagellate cysts from the Upper Cretaceous–lower Paleocene succession in the western External Rif,Morocco: New species and new biostratigraphic results

Palynological investigation of the Upper Cretaceous–lower Paleocene succession from the Tahar section near Arba Ayacha in northwestern Morocco (westernmost External Rif Chain) reveals the presence of rich, diverse and well-preserved dinoflagellate cyst assemblages. For the first time in the study region, biostratigraphic interpretations based on the dinoflagellate cyst assemblages from the studied interval allow the recognition of the upper Maastrichtian and Danian. Relevant upper Maastrichtian–Danian global dinoflagellate cyst events include: the First Appearance Datum of the upper Maastrichtian species Disphaerogena carposphaeropsis, Glaphyrocysta perforata, and Manumiella seelandica; the Last Appearance Datum of the Cretaceous taxa Dinogymnium spp., Isabelidinium cooksoniae, and Pterodinium cretaceum; and the First Appearance Datum of the earliest Danian markers Carpatella cornuta, Damassadinium californicum, Membranilarnacia? tenella, and Senoniasphaera inornata. We formally describe the biostratigraphical range and potential of two new dinoflagellate cyst species, namely Nematosphaeropsis silsila Guédé and Slimani nov. sp., and Pterodinium ayachensis Guédé and Slimani nov. sp. Both species are found in the westernmost External Rif Chain and are restricted to the upper Maastrichtian.     

Venezuelines A–G,new phenoxazine-based alkaloids and aminophenols from Streptomyces venezuelae and the regulation of gene target Nur77

Five new phenoxazine-based alkaloids venezuelines A–E (1–5) and two new aminophenols venezuelines F–G (6–7), as well as three known analogues exfoliazone, chandrananimycin D and carboxyexfoliazone were isolated from the fermentation broth of the marine-derived bacterium Streptomyces venezuelae. The structures of new compounds were determined on the basis of extensive spectroscopic analysis. The cytotoxic activity of these compounds against a panel of tumor cell lines were tested, while the regulation of gene target Nur77 of 2 and exfoliazone (8) were evaluated.     

Quiquelignan A–H,eight new lignoids from the rattan palm Calamus quiquesetinervius and their antiradical,anti-inflammatory and antiplatelet aggregation activities

Eight new lignin derivatives, termed quiquelignan A–H (1–8), comprising three tricin-type flavonolignans (1–3) and five 8-O-4′ neolignans (4–8), were isolated from the ethanol extract of Calamus quiquesetinervius stems. Structural elucidation of the new isolates was accomplished on the basis of spectroscopic data. Compounds 1–8 showed strong-to-moderate antioxidant activity against the hydroxy radical (OH). Among them, compound 5 showed significantly higher hydroxy radical scavenging activity (IC₅₀ 4.4 μg/mL). Compounds 2–4 and 6–8 dose-dependently suppressed the LPS-stimulated production of nitric oxide (NO) in RAW 264.7 cells. The anti-inflammatory potency of 4 and 6 was 2.7–4.5-fold higher compared with quercetin. Compounds 2–4, 6 and 8 also exhibited mild collagen-antagonistic activity, but were inactive with respect to thrombin-induced platelet aggregation.     

Review of the cichlid genus Thysochromis (Teleostei: Ovalentaria) with the description of a new species from the Kouilou Province in the Republic of Congo,west–Central Africa

A new species of the chromidotilapiine genus Thysochromis, is described from the Noumbi and Kouilou River drainages in the Republic of Congo. Based on the current investigation, Thysochromis is resolved as containing two geographically disjunct species, T. ansorgii from localities in the upper Guinean ichthyofaunal province (Ivory Coast, Ghana, Benin and Nigeria) and Thysochromis emili sp. nov. restricted to coastal regions of the Republic of Congo in the lower Guinean province.