Palaeoginkgoxylon zhoui, a new ginkgophyte wood from the Guadalupian (Permian) of China and its evolutionary implications

A new taxon of ginkgophyte affinity Palaeoginkgoxylon zhoui gen. nov. et sp. nov. is described from the Guadalupian Lower Shihhotse Formation of the Hulstai coalfield, Inner Mongolia Autonomous Region (Nei Mongol), northern China, on the basis of the anatomical structures of the broad eustele and pycnoxylic secondary xylem. The anatomical structure of the new woody tree trunk resembles both the early gymnosperms of Eristophyton-Pitus types and the modern Ginkgo. Therefore, the new tree trunk is interpreted as representing a transitional stage in the evolution of Ginkgo from early arborescent lignophytes since the Early Carboniferous.     

A biogeographically mixed, Middle Permian brachiopod fauna from the Baoshan Block, western Yunnan, China

A small brachiopod fauna is described from the carbonate rocks of the basal Shazipo Formation of the Baoshan Block, western Yunnan, south-west China, including significant new ventral and dorsal internal morphological features of Cryptospirifer omeishanensis Huang. This fauna is regarded as Wordian (Middle Guadalupian, Middle Permian) because of the presence of Cryptospirifer omeishanensis Huang and associated fusulinids ( Neoschwagerina craticulifera Zone). Palaeobiogeographically, the brachiopod fauna is of considerable interest because of its admixed nature characterized by typical warm-water Cathaysian elements intermingled with temperate Peri-Gondwanan taxa. This in turn is interpreted to indicate that the Baoshan Block may have been situated in an intermediate palaeogeographical position between Gondwanaland to the south and Cathaysia to the north during the Mid Permian and, as such, it probably furnished an important 'stepping stone' for the dispersal of Mid Permian eastern Tethyan marine invertebrate taxa (e.g. Cryptospirifer ) to the western Tethys.     

New latest Permian foraminifers from Laren (Guangxi Province, South China): Palaeobiogeographic implications

Microfacies analyses performed on the latest Permian Wujiaping Formation at Laren (Guangxi Province, South China) show that the bioclastic-rich limestones of Late Permian age contain a rich and well-diversified foraminiferal fauna. This fauna is here revised in order to be compared with time-equivalent levels of southern Iran and southern Turkey. Some new and unexpected phylogenetic trends are highlighted among the biseriamminoids. The new or poorly known genera Retroseptellina, Septoglobivalvulina, Paraglobivalvulinoides, Dagmarita?, Bidagmarita nov. gen., Louisettita, Paradagmaritopsis nov. gen. and Paradagmarita? are concerned. Nevertheless, these newly appeared biseriamminoids are subordinate to abundant Tetrataxis and Climacammina, ultimate survivors of the families Palaeotextulariidae and Tetrataxidae, appeared as old as the Early Carboniferous (“Mississippian”). Algae, miliolids, and nodosarioids are poorly represented. Two genera and four species are here newly described: Globivalvulina curiosa nov. sp., Louisettita ultima nov. sp., Bidagmarita nov. gen., Bidagmarita sinica nov. gen. nov. sp., Paradagmaritopsis nov. gen., Paradagmaritopsis kobayashii nov. gen. nov. sp. The palaeogeographic distribution of these foraminifers is interpreted to be typically of Neo-Tethyan regions, ranging from southern Turkey (Hazro) to South China (Laren) and up to Japan for some species (i.e., Paradagmaritopsis). At Laren, Late Permian strata are generally characterized by Reichelina ex gr. simplex Sheng. Isolated samples of packstones, collected in Tsoteng region (Guangxi Province, South China), contain Sphaerulina sp. together with various smaller foraminifers and numerous representatives of the new species G. curiosa nov. sp. In this study we demonstrate that the regions of Zagros (Iran), Taurus (Turkey), South China and even Japan shared similar foraminiferal assemblages and represented intermittently connected palaeobiogeographic provinces during Late Permian times.     

The Shanita fauna (Permian foraminifera) from Baoshan area, western Yunnan Province, China

Studies in the past decade have proven the Shanita fauna to be an excellent marker of the northern peri-Gondwana tectonic blocks. Thus, a study of the Shanita fauna from the Baoshan area in western Yunnan Province, China, could provide pivotal paleontological evidence for the paleogeographic reconstruction of the Baoshan block. We systematically analyzed the composition and the age of the Shanita fauna from the Permian Da’aozi Formation in Woniusi Section of the Baoshan area. Results suggested that the characteristic genera Shanita and Hemigordiopsis in this fauna comprised eight species (including two new species), and ten genera of other nonfusulinid foraminifera were also recognized from this fauna. Further comparative study showed that the Shanita fauna from the Baoshan area were probably late Maokouan (Lengwuan) to Wuchiapingian in age. In general composition, this fauna is comparable to those Shanita faunas from Shan State of Burma, Peninsular Thailand, and Nagri of Tibet, China. However, the relatively low generic diversity and occurrence of some endemic species, as well as the absence of fusulinids, indicate certain regional features of the Shanita fauna from the Baoshan area. Translated from Acta Palaeontologica Sinica, 2005, 44(4): 545–555 [译自: 古生物学报]     

Microfacies of a Permian calcisponge reef in Lichuan,western Hubei,South China

The Lichuan Jiantianba reef is located at the platform margin between the carbonate platform and the marine trough in western Hubei, China. The water depth of this area became shallow in the late Permian Changhsingian Age, and a huge aggradation-progradation platform marginal reef developed. Based on precise field measurements and microscopic observation, this paper describes the petrological characteristics and biological assemblages of the reef in detail and distinguishes 10 microfacies: small echinoderm wackestone, sponge floatstone, bound sponge bioliestone, bound sponge framestone, large echinoderm wackestone, red algal limestone, bioclastic grainstone, dasycladales wackestone, shelly wackestone, and microbialites. Sponge floatstone and bound sponge bioliestone are defined as toppled sponge limestone. Comparisons of the petrological characteristics and biotic association of toppled sponge limestone, bound sponge framestone and bioclastic wackestone and grainstone revealed that the toppled sponge limestone and the bound sponge framestone are similar in sponge content in terms of the types and contents of reef-dwellers, except that the sponge content is slightly lower, and the preservation state is mainly toppled for the former and upright or inclined for the latter. The toppled sponge limestone is dominated by tabular calcite, and the bound sponge framestone is dominated by fibrous calcite. The bioclastic wackestone and grainstone do not contain reef-building sponge organisms, and the bioclast content is very high and often dominated by a certain class, such as echinoderms, foraminifers, green algae or shells. The toppled sponge limestone below the framework, which was classified as fore-reef breccia or bioherm bafflestone-bindstone in previous studies, should be defined as reef-core sponge limestone deposited in situ that experienced serious post-karstification. The vertical evolution of the sedimentary facies of the reef is analyzed based on the microfacies and sedimentary environment. The toppled sponge limestone and the bound sponge framestone should be classified as reef core, which is the only subfacies of the reef facies. The underlying small echinoderm wackestone should be classified as the shelf facies, whereas the overlying bioclastic wackestone and grainstone should be classified as the open platform facies. These classifications represent a modification of the sedimentary facies subdivision of the Jiantianba reef in Lichuan, Hubei Province, South China, and provide a new reference model for the subdivision of the Permian calcisponge reefs on platform margin.     

Charred wood of Prototaxoxylon from the Wuchiapingian Wutonggou Formation (Permian) of Dalongkou,northern Bogda Mountains,northwestern China

Charred wood occurs sporadically in sedimentary rocks in China. A marcroscopic charcoal with well-preserved anatomical structure is described from the Wuchiapiangian Wutonggou Formation in the southern part of Dalongkou section, northern Bogda Mountains in the Junggar Basin, northwestern China. It is characterized by uniseriate radial tracheidal pitting, taxaceous tertiary spiral thickenings in the tracheidal walls, uniseriate tangential tracheidal pitting, homogeneous, uniseriate, 2–10 cells high xylem rays, and 1–2 pits in each cross-field. It is assigned to Prototaxoxylon uniseriale Prasad. The uniseriate, bordered, contiguous, rarely separate tangential pitting of P. uniseriale is evidenced clearly for the first time. The features of this species show a close affinity with conifers. The coniferous charred wood may have been derived from an extrabasinal forest, perhaps from upland environment deep within the hinterland, according to results of modern taphonomic research.     

Permian and Triassic Radiolaria from Northwest Thailand: paleogeographical implications

Well-preserved radiolarians were recovered from seven sections in the Mae Hong Son-Mae Sariang area, northwestern Thailand. 51 species assigned to 34 genera are identified, including 1 new species (Triassospongosphaera erici Feng sp. nov.) and 19 unidentified species. They are divided into the Late Permian, late Ladinian and middle Carnian radiolarian assemblages. Newly identified radiolarian assemblages, together with the published radiolarian biostratigraphic data from this region, indicate that there was a pelagic basin during the Late Paleozoic and Triassic. This basin was joined to the Chiang Dao and Changning-Menglian oceanic basins, and they represent the main oceanic basin of the Paleotethyan Archipelago Ocean. This main oceanic basin was situated in the traditional “Shan-Thai Block”. Therefore, “the Shan-Thai Block” was not a single block during that stage, but composed of the Paleotethyan Ocean and two continental terranes that were affiliated with the Gondwana and Cathaysian domains, respectively.     

GIgantonoclea: an enigmatic Permian plant from North China

Gigantonoclea is a distinctive and enigmatic plant from the Permian of North China proper, with an unusual frond architecture and a pollen organ and vascular structure which are unique; it demonstrates a sudden rise and a rapid extinction. This paper reviews previous work on Asian gigantopterids and describes new material from the Upper Permian of Shanxi Province, including a new type of pollen organ (Jiaochengia lagrelii) and two new species of frond (Gigantonoclea crenataG. pubescens). Jiaochengia shows opposite, dissected and rather modified microsporophylls, laxly aggregating into an independent organ, which is markedly different from ‘Gigantotheca’ from Fujian. This presents evidence of heterogeneity among Asian gigantopterids and partly supports a relationship with the Carboniferous Callistophytales. Jiaochengia sporangia have what may be the first record of a waxy covering on the outer surface of a fossil plant, which is interpreted to have functioned to repel water, to protect against fungal attack and to scatter light. According to Hickey's rule, the venation of true Gigantonoclea fronds consists of three orders of main veins (rachis, midvein and secondary veins) and two orders of anastomosing veins (tertiary veins and veinlets). Certain putative ‘Gigantonoclea’ species from South China and some peripheral areas of North China do not have this type of venation and are thus excluded from the genus. Frond dimorphism is common among gigantopterids in both North and South China and can be compared with the amphibious variation from submerged to emergent leaves in extant aquatic plants. G. pubescens has a thick, bi-layered adaxial cuticle with an indumentum covering with dense papillae and trichomes bases, and deeply sunken, papillate stomata, suggesting that it favoured more arid conditions. An observed gradient from pubescent to glabrate or even glabrous gigantopterid cuticle structures between North and South China suggests a change from xeric, mesic to humid habitats.     

Gas diffusion through wood: implications for oxygen supply

Living tissue in tree stems has to be supplied with oxygen, which can be transported upwards with the transpiration stream; but in times of zero sapflow, the only source is the oxygen stored or diffusing radially through bark and xylem. We measured radial and axial diffusion of oxygen against nitrogen gas in wood of coniferous (Picea abies (L.) Karst. and Taxus baccata L.), ring-porous (Quercus robur L. and Fraxinus excelsior L.) and diffuse-porous (Fagus sylvatica L. and Carpinus betulus L.) trees at different water and gas contents in the laboratory. The diffusion coefficient (D) in radial direction was mostly between 10⁻¹¹ and 10⁻⁷ m² s⁻¹ and was strongly related to the gas content. At 40% gas volume, D increased 5–13-fold in Picea, Taxus and Quercus, 36-fold in Fraxinus, and about 1000-fold in Carpinus and Fagus relative to D at 15% gas volume. In the axial direction, diffusion was 1 or 2 orders of magnitude faster. Between-species differences in diffusion velocities can largely be explained by wood structure. In general, D was lowest in conifers, highest in diffuse-porous and intermediate in ring-porous hardwoods, where the large vessels were mostly blocked by tyloses. Model calculations showed that at very high water content, radial diffusion can be too low to ensure the supply of respiring sapwood with sufficient oxygen and an important function of gas in living stems appears to be the supply of oxygen through storage and diffusion.     

Aragonitic dasycladalean algae from the Upper Permian of Sichuan, China

Exceptionally well-preserved specimens of Mizzia yabei (Karpinsky) were discovered in bituminous packstone intercalations of the early Upper Permian Maokou Formation of Anxian County (Sichuan, China). Staining techniques and x-ray diffraction reveal that the organic encrustation around the central stem and the lateral branches consists of aragonite. Average aragonite contents range between 27% and 40%. The bulk of the remaining 60–73% calcite represents cement. The total Sr-content is 3, 400 ppm, indicating 8,000–10,000 ppm for the aragonite fraction. The organically precipitated aragonite was deposited as closely packed fibres, 10–20 μm long and 0.5–1 μm wide. The fibres are arranged in clinogonal (water-jet) fascicles, which diverge towards the central (spar-filled) stem. This microstructure shows that the mineralization of the mucilage started at the periphery of the extracellular encrustation and progressed toward its interior. Diagenetic alterations of the original aragonite include various stages of breakdown of the fibres into 0.5–1 μm large granules (micritization), minor syntaxial growth of the fibres and local transformation of acicular aragonite into neomorphic calcite. The dasycladaleans from the Permian of Sichuan appear to be by far the oldest representatives of this order with preserved aragonitic mineralogy and microstructure. Comparably well-preserved examples are only known from Eocene and younger deposits.     

Lopingian (Upper Permian) trace fossils from the northern Penglaitan Section,Laibin, Guangxi,South China and their environmental implications

The end-Permian mass extinction has been widely documented to be accompanied with oceanic anoxia, which was considered as one of the most plausible killing mechanisms. However, it is still unclear when anoxia began to occur and how widely affected during the pre-extinction interval. In this study, Lopingian bottom-water oxygen level changes around the Wuchiapingian–Changhsingian boundary (WCB) at the northern Penglaitan section in Guangxi are analysed based on trace fossil assemblages and ichnofabric indices. Detailed bed-by-bed ichnological analyses confirm the presence of trace fossils Chondrites intricatus, C. isp., Palaeophycus isp., Planolites isp. A, P. isp. B, Thalassinoides isp. A, T. isp. B, Trichichnus linearis, Zoophycos isp., and other bioturbational structures. The ichnofabric indices around the WCB are mostly 1–2, but rapidly increase to 4–5 in some short intervals. The distinct fluctuations of ichnofabric indices suggest that the oxygen level of sediments was generally deficient, but the dysoxic or anoxic periods were punctuated by several short oxic intervals. Thus, it can be inferred that the benthic organisms were under secularly environmental stresses around the WCB at the northern Penglaitan section. The anoxic conditions unfavourable for aerobiosis in the deep basin may start in the late Wuchiapingian. However, more sections need to be studied to determine whether this is a local or regional phenomenon.     

Bioerosion in Late Permian Rugosa from reefal blocks (Hawasina Complex,Oman Mountains): implications for reef degradation

Summary Rugose corals are known from allochthonous Late Permian reefal blocks of the A1 Jil and Ba’id Formation (Hawasina Complex), Oman Mountains. In contrast to many Late Permian Rugosa found elsewhere in the Tethys, they occurred in sponge reefs and contributed to reef construction. The waagenophyllid warm water coral fauna is moderately diverse comprising cerioid, thamnasterioid, and fasciculate taxa. In contrast to sponges, chaetetids, and low-growing reefbuilders, the corals secreted diagenetically stable, most probably Mg-calcitic skeletons. Borings in coral skeletons are consequently well preserved providing important data for the interpretation of reef destructive processes. Thin-section analysis revealed three taxa of infaunal borers includingEntobia Bronn 1837, uncertain thallophyte borings, and borings of unknown bioeroders. Macroborers were more important than microborers, because of the dominance of clionid sponges. Good evidence exists also for the occurrence of two types of undetermined grazers which destroyed the coral surfaces. The amount and distribution of bioerosions is variable among different coral taxa. The fasciculate coralPraewentzelella regulare Flügel 1995 was the favorate substrate. Up to 33% of the calices were bored. Dendroid and compound corals were bored subordinately. Bioerosion of these colonies does not exceed 2%. There is good evidence for substrate preference amongst the borers. Major controlling factors affecting borer distribution are believed to be variations of skeletal density and gross morphology. The borer assemblage could not limit reef accretion significantly. Factors controlling boring activity might have been quality of substrate, sedimentation rate, rapid incrustation of substrates, and competition for food with reef constructors including sponges, chaetetids, and rugose corals.     

Wood cell walls: biosynthesis, developmental dynamics and their implications for wood properties

Progress has been made toward understanding the biosynthesis and modifications of the cellulose and the hemicellulose/pectin matrix of woody cell walls (and hence wood properties) by identifying 1600 carbohydrate active enzymes (CAZYmes) in Populus, and pinpointing key candidates involved in various developmental stages of wood formation. Transgenic modifications of primary wall modifying enzymes have demonstrated on the possibility of shaping the dimension of wood cells. Candidates for the biosynthesis of secondary wall matrix have been identified, and the cellulose microfibril angle of wood fibers has been modified. In addition, molecular analysis of the plastic development of wood cell walls has provided further information regarding the mechanisms regulating their structure.     

Lunar cycle and psychiatric hospital admissions for schizophrenia: new findings from Henan province,China

ABSTRACT

Objective: Findings on the effect of the lunar cycle on mental illness are conflicting. We investigated the association between the lunar cycle and a number of psychiatric presentations of schizophrenia and determined which subtypes were susceptible to lunar phases.

Methods: We evaluated 13,067 patients admitted to Zhumadian Psychiatric Hospital between January 1, 2012, and December 31, 2017 (73 lunar cycles). Patients were retrospectively assigned to lunar phase based on their admission date: new moon +/? 1 day, first quarter +/? 1 day, full moon +/? 1 day, and third quarter +/? 1 day. The International Statistical Classification of Diseases, 10th revision (ICD-10), was used for diagnosis. We used a Chi-squared goodness of fit test to evaluate the distribution of admissions across the lunar phase and R*C Chi-squared tests to compare age, sex, birth season, and clinical subtype distributions by phase. We used multiple logistic regression to further identify the relationship between clinical subtype and lunar phase.

Results: Psychiatric admissions for schizophrenia varied significantly across the lunar cycle (χ² = 36.400, p< .0001), peaking in the first quarter, followed by the full moon, and lowest at the new moon. Using unspecified schizophrenia (F20.9) as reference, people with paranoid schizophrenia (F20.0) were more likely to be admitted in the full moon than in other phases (odds ratio: 1.157, 95% confidence interval: 1.040–1.286) (p < .05); other subtypes showed no admission differences during the four lunar phases (p > .05).

Conclusions: Psychiatric admissions for schizophrenia show lunar periodicities. People with schizophrenia tend to be stable in the new moon, but their condition is easily aggravated during the first quarter and full moon. Patients with paranoid schizophrenia are more susceptible to deterioration at the full moon, so merit more attention and care from communities, families, and hospitals.     

Chromosomal characterization of Arvicanthis species (Rodentia,Murinae) from western and central Africa: implications for taxonomy

A chromosome study of unstriped grass rats of the genus Arvicanthis (Rodentia, Murinae) in western and central Africa is presented. The observations extend the data available to 242 specimens from 59 localities. All individuals karyotyped belong to four karyotypic forms, or cytotypes, earlier described as ANI-1, ANI-2, ANI-3, and ANI-4 and are presumed to correspond to four distinct species. In order to provide diagnostic characters for these western and one central African Arvicanthis species, we standardized the chromosomal data available and developed a G- and C-banded chromosome nomenclature that allows easy species identification. Each form is characterized by a distinct geographical distribution, roughly following the biogeographical domains of western Africa, although their precise limits remain to be assessed. The sole area of sympatry detected is the region of the inner delta of the Niger River, where both ANI-1 and ANI-3 can be found. It is proposed that the three western African species ANI-1, ANI-3, and ANI-4 be renamed as A. niloticus, A. ansorgei, and A. rufinus, respectively.     

中国二叠纪煤核中具解剖构造的鳞木类植物:似封印叶属(英文)

报道了产于中国二叠纪煤核中的 3种具解剖构造的鳞木类叶 ,它们都具双木质部束 ,与似封印叶属 (Sigil lariopsisScott)特征一致。与该属已有种进行了对比 ,确认它们为 3个新种 :产于山西太原西山煤田太原组上部 7号煤层 (早二叠世早期 )煤核中的山西似封印叶 (Sigillariopsisshanxiensissp .nov .)和太原似封印叶 (S .taiyuanensissp .nov .)以及产于贵州水城矿区汪家寨组 1号煤层 (晚二叠世晚期 )煤核中的贵州似封印叶 (Sigillariopsisguizhouensissp .nov .)。根据煤核中共生的鳞木类植物其他器官以及欧美植物区鳞木类植物的研究资料推断 ,它们可能属于封印木属 (SigillariaBrongniart)的叶。在国外 (主要是欧美植物区 ) ,封印木属植物主要分布于石炭纪 ,见于二叠纪的封印木很少。华夏植物区的封印木属过去很少发现 ,其叶和生殖器官均未报道过。本文是首次报道华夏植物区具解剖构造的封印木属的叶 ,它们的发现不仅丰富了华夏植物区封印木属植物的内容 ,而且对于研究封印木属的演化以及华夏植物区与欧美植物区鳞木类植物之间的关系也具有重要的意义。     

Latest Permian Palaeolithocycliidae (Radiolaria) from South China

The family Palaeolithocycliidae Kozur and Mostler was formerly thought to be ranging from Devonian to Carboniferous. However, a lot of radiolarians assignable to this family were discovered in the late Changhsingian (Latest Permian) of South China. Six species, including Palaeolithocyclia pilata n. sp., Palaeolithocyclia platta n. sp., Paramphibrachium woni n. sp., Klaengspongus spinosus Sashida, Klaengspongus formosus n. sp. and Klaengspongus umbilicatus n. sp., have been identified. In this paper, these species are illustrated and described.     

A large anatomically preserved calamitean stem from the Upper Permian of southwest China and its implications for calamitean development and functional anatomy

A large permineralized calamitean stem, Arthropitys yunnanensis Tian et Gu from the Upper Permian of southwest China is reinvestigated and interpreted. The stem has a broad pith and well developed and large carinal canals. Secondary xylem is thick and characterized by wide parenchymatous interfascicular zones that remain constant in width throughout the wood. Striking features of the stem include the abundant leaf traces arranged in two whorls in the cortex with this arrangement previously unrecognized within calamitean stems, and the presence of growth rings in secondary xylem that suggest frequent fluctuations in environmental stress presumably due to variations in water availability. Features of A. yunnanensis infer the stem to be in the epidogenetical phase of calamitean development, and suggest it to be the basal part of a large trunk. Comparisons with biomechanical models for calamitean stems suggest this species had a semi-self supporting habit.     

Todea from the Lower Cretaceous of western North America: implications for the phylogeny, systematics, and evolution of modern Osmundaceae

The first fossil evidence for the fern genus Todea has been recovered from the Lower Cretaceous of British Columbia, Canada, providing paleontological data to strengthen hypotheses regarding patterns of evolution and phylogeny within Osmundaceae. The fossil consists of a branching rhizome, adventitious roots, and leaf bases. The dictyoxylic stem has up to eight xylem bundles around a sclerenchymatous pith. Leaf traces diverge from cauline bundles in a typical osmundaceous pattern and leaf bases display a sheath of sclerenchyma around a C-shaped xylem trace with 2-8 protoxylem strands. Within the adaxial concavity of each leaf trace, a single sclerenchyma bundle becomes C-shaped as it enters the cortex. The sclerotic cortex is heterogeneous with an indistinct outer margin. The discovery of Todea tidwellii sp. nov. reveals that the genus Todea evolved by the Lower Cretaceous. A phylogenetic analysis combining morphological characters of living and extinct species with a previously published nucleotide sequence matrix confirms the taxonomic placement of T. tidwellii. Results also support the hypothesis that Osmunda s.l. represents a paraphyletic assemblage and that living species be segregated into two genera, Osmunda and Osmundastrum. Fossil evidence confirms that Osmundaceae originated in the Southern Hemisphere during the Permian, underwent rapid diversification, and species extended around the world during the Triassic. Crown group Osmundaceae originated by the Late Triassic, with living species appearing by the Late Cretaceous.