Following the extinctions caused by the end-Ordovician (Hirnantian) glaciations, the world gradually returned to warmer climates, together with rising eustatic sea levels. As a result of those changes, benthic faunas steadily increased in diversity through the Early Silurian (Llandovery Series),and of those faunas, brachiopods are the most abundant. Recently, Professor RONG Jiayu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and Professor Robin Cocks from Natural History Museum, London, UK reviewed Silurian brachiopods of Middle Llandovery (Aeronian) ages. More than 200 genera are identified, compared with 109 in the preceding Early Llandovery (Rhuddanian), indicating a recovery-radiation interval after the end-Ordovician mass extinction. The chief regions in which they are found are the continents of South China, Avalonia-Baltica, Laurentia and Siberia, which were all at tropical latitudes with the exception of Avalonia. In addition, the very large super terrane of Gondwana, although with patchy brachiopod distribution, included temperate faunas, as well as subtropical faunas (in Iran and Afghanistan). Aeronian brachiopods greatly increased in diversity, with dominance of four major groups: orthides and strophomenides(which had flourished previously in the Rhuddanian), pentamerides and atrypides (which became dominant in the Aeronian), and many newly evolved taxa, and occupied deeper water and wider ecological niches (level bottom and reef) than those in the Rhuddanian. Each of the continents has some endemic genera, but there is agreater proportion of them in South China, where some groups (such as the pentamerides and atrypides) are more diverse and others, such as the orthides, are much less common than elsewhere. Affinity indices (AI) show that two megaunits can be recognized: South China and Avalonia-Baltica-Laurentia (ABL); Siberia seems to have been loosely connected with ABL and even more loosely to South China presumably because of its geographical separation in the Northern Hemisphere. The separation of South China from the other megaunits is further supported by cluster analysis. The research results have been published in Lethaia ( RONG Jiayu, Cocks L.R.M. 2014: Global diversity and endemism in Early Silurian (Aeronian) brachiopods. Lethaia, Vol. 47, pp. 77–106.)
Global palaeogeography in the Early Silurian at about 440 Ma, with the names of thecontinents discussed. WNEC andWSEC are ‘Western North Equatorial Currents’ and ‘Western South Equatorial Currents’.
The Kwangsian Orogeny was first proposed by Prof. Ting V K (Ding Wenjiang) in 1929. It originated along the southeast coast of China and stepwise developed in a northwestern direction. Based on a precise biostratigraphic study, two stages of the Kwangsian Orogeny were recognized: a long, locally varying uplift from the Late Ordovician to the early Silurian, and a finally tectonic movement near the Silurian and Devonian transition. The Kwangsian uplift event shows a stepwise delay northwestwards from the southeastern coast area in the Nemagraptus gracilis Biozone to the south side of the Xuefeng Mountains in or later than the Cystograptus vesiculosus Biozone to the Coronograptus cyphus Biozone. In the south of the Yangtze Platform, the Yichang Uplift was driven by the Kwangsian Orogeny forming a diachronous stratigraphical break through Rhuddanian and Aeronian. The research article by Professor CHEN Xu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues was published as a cover paper of the Science China: Earth Sciences. Detailed information: CHEN Xu, FAN Junxuan, CHEN Qing, TANG Lan, HOU Xudong. 2014. Toward a stepwise Kwangsian Orogeny. Science China: Earth Sciences, 57(3): 379-387, doi: 10.1007/s11430-013-4815-y
Ordovician and Silurian correlation from the southeastern coast of China to the Yangtze region through the Xuefeng-Jiuling Mountains
Northwestward stepwise uplift of the Kwangsian Orogeny from the southeastern coast of China to the Yangtze region through the Xuefeng-Jiuling Mountains
The family Osmundaceae is significant among ferns due to its extensive fossil record with more than 200 species. Among them, over 80 species are recognized based on permineralized rhizome specimens. Compared to fossil foliages, the permineralized materials are crucial for studying the classification, phylogeny and evolution of the Osmundaceae because they bear more anatomical and phylogenetic information. However, the anatomical diversity and phytogeographic history of the fossil Osmundaceae are not well understood. A new fossil species, Ashicaulis plumites has been recognized from the Middle Jurassic in western Liaoning, NE China by Professor WANG Yongdong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his research team. This result has been published in a recent issue of Springer journal Journal of Plant Research.
This new species is characterized by a specialized petiolar structure yielding a sclerenchyma mass with a distinctive outward protuberance in the petiolar vascular bundle concavity, which distinguishes the present new species from other Ashicaulis species. Such a protuberance has been only observed in Osmunda pluma Miller from the Palaeocene of North America, and represents a distinct type for sclerenchymatous tissue in the osmundaceous vascular bundle concavity. The specialized structure of this new fossil species enriches anatomical diversity of permineralized osmundaceous ferns, indicating that the family Osmundaceae might have experienced a remarkable diversification during the Middle Jurassic in NE China.
Detailed information: Tian, N., Wang, Y.D.*, Philippe, M., Zhang, W., Jiang, Z.K., Li L.Q., 2014. A specialized new species of Ashicaulis (Osmundaceae, Filicales) from the Jurassic of Liaoning, NE China. Journal of Plant Research, 127: 209-219 (* corresponding author).
The anatomical characteristics of Ashicaulis plumites (sp. nov.)
The specialized petiolar structure of Ashicaulis plumites (sp. nov.)
Variation of sclerenchyma mass of Ashicaulis plumites (sp. nov.)
Insects are the most diverse group of animals on Earth today, and also have an extensive fossil record from the Carboniferous to recent. Interpretation of fossil insects and reconstruction of their paleodiversity must consider the taphonomic processes involved because decay influences the preserved morphology, which strongly affects diversity estimates. Furthermore, the taphonomy of insects is essential to interpreting the paleoecology and paleoenvironment. Various intrinsic as well as extrinsic factors significantly control the preservation of insects. Few studies have presented a quantitative comparison of biostratinomic patterns in different groups. Associate Professor WANG Bo and Professor ZHANG Haichun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues systematically investigated the preservation of 277 specimens of Palaeontinidae and 113 of Tettigarctidae, two hemipterous families from the Jurassic Daohugou beds lacustrine Konservat-Lagerst？tte. They carried out quantitative analyses of their size and taphonomic characters, including body orientation, articulation, and preservational quality, and also performed a preliminary experiment to understand the floating and decay process of cicadas. Their statistical analyses reveal significant differences in both body orientation and preservational quality between the two families. Palaeontinidae experienced longer flotation time (mostly over one month) before settling through the water column due to their high SM index (wing surface/body mass ratio) and unfolded wings, increasing the opportunity to decompose on the water surface and resulting in the dorsoventral preservational position with lower preservational quality. In contrast, Tettigarctidae have a comparatively low SM index and overlapping wings, so that their drifting period on the water surface might have been short (mostly within 2 weeks), leading to the lateral preservation position with higher preservational quality. Their taphonomic variations were controlled by different SM indices and wing folding modes. The biological factors recognized may control taphonomic patterns in other fossil insects with similar body forms and wing folding patterns. Insects sometimes possess very different ecological traits and morphological characteristics. The results suggest that these differences may determine their preservation patterns by controlling their taphonomic processes, such as transport distance, floating time, and decay rate. Different taxonomic groups of insects may have different taphonomic processes, leading to contrasting preservational patterns and taphonomic bias. The taphonomic variability of insects at family level should be noted in future taphonomic studies. In addition, the wing folding behavior and subsequent different modality of fossilization between these two groups also introduced another difficulty during the taxonomic study, i.e. important wing venation characters are mainly obscured in the Tettigarctidae. The taphonomic variability should, therefore, betaken into account in future studies of paleodiversity estimation and paleoecological reconstruction of fossil insects. Related information of this paper: Wang Bo, Zhang Haichun, Jarzembowski E.A., Fang Yan, Zheng Daran (2013) Taphonomic variability of fossil insects: a biostratinomic study of Palaeontinidae and Tettigarctidae (Insecta: Hemiptera) from the Jurassic Daohugou Lagerst？tte. PALAIOS, 28: 233–242.
Professor YIN Leiming from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues recently made a new progress in the search for Cambrian ‘Cryptospore-like’ microfossils which has been selected as the cover of the SCIENCE CHINA Earth Sciences. Abundant specimens of cryptospore-like microfossils, including dyads, tetrads and monads, have been collected by palynological maceration from rock sample of the “Middle” Cambrian Log Cabin Member of the Pioche Shale in eastern Nevada, USA. Some specimens preserved in situ were observed by using SEM. Compared with organic-walled microfossils obtained from the Cambrian Kaili Formation in eastern Guizhou Province, China, some specimens of leiosphers may be inferred to be similar cryptospore-like microfossils. The new fossil record would be the oldest known specimens of cryptospore-like microfossils during the Cambrian Period. The Cambrian cryptospore-like microfossils might have originated from quite shallow water plant sporoderm forms. Although the Cambrian cryptospore-like microfossils have been recovered with a primitive spore wall structure as “protoembryophytes”, their phylobiology and living habits still require additional fossil discoveries to confirm their paleoecology and phylogeny. Related information of this paper: YIN LeiMing, ZHAO YuanLong, BIAN LiZeng, PENG Jin, 2013, Comparison between cryptospores from the Cambrian Log Cabin Member, Pioche Shale, Nevada, USA and similar specimens from the Cambrian Kaili Formation, Guizhou, China. SCIENCE CHINA Earth Sciences, 2013, 56(5): 703-709
The Staphylinidae, or rove beetles, is the most species-rich family known on the planet, comprising 32 subfamilies and more than 58 000 described species. The Mesozoic staphylinids are of great significance for understanding the origin and early evolution of the whole family. The Mesozoic terrestrial strata are well developed in the territory of Transbaikalia, Russia. Since Dr. Ryvkin reported some staphylinids from the region in 1990, no additional impression fossils have been reported from this region. Recently, a PhD student CAI Chenyang and Dr. E. V. YAN from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences together with Dr. D. V. VASILENKO from Borissiak Paleontological Institute, Russian Academy of Sciences, reported a new rove beetle species, Sinoxytelus transbaicalicus, from the Urey locality (Urey beds, Early Cretaceous?), Transbaikalia, Russia. The genus Sinoxytelus was originally described in 2010 by Dr. YUE Yanli from Capital Normal University, and it was placed in the modern oxyteline tribe Oxytelini. Sinoxytelus is a dominant genus in the Early Cretaceous Yixian Formation (approximately 125 million years ago [mya]) of northeastern China, comprising over 50% of all specimens collected from this formation. Sinoxytelus is only confined to the Early Cretaceous Jehol biota and absent in the Middle Jurassic Daohugou biota (approximately 165 mya) and the Late Jurassic Karatau beds (approximately 155 mya). Both SEMs and light microscope are applied for the new specimen recovered from the Urey locality, finding that it represents a new species of Sinoxytelus and it is well separated from other representatives by possessing a relatively large head, transverse pronotum, and slightly tapered abdomen. This is not only the first find of the extinct genus Sinoxytelus outside of China, extending its paleogeographic distribution, but also suggests that the Urey beds are probably Cretaceous in age. In addition, according to comprehensive comparisons between the new species and other congeners, the systematic position of Sinoxytelus in the extant subfamily Oxytelinae is transferred from the tribe Oxytelini to the more basal tribe Coprophilini. This new find sheds new lights on the origin and early evolution of the staphylinid subfamily Oxytelinae. Related information of this paper: Cai, C. -Y., Yan, E. V., Vasilenko, D. V. (2013) First record of Sinoxytelus (Coleoptera: Staphylinidae) from the Urey locality of Transbaikalia, Russia, with discussion on its systematic position, Cretaceous Research 41: 237–241.
It has been known for long in a famous book <Evolution of the Insects> that the most puzzling fossil insects are Saurophthirus and Strashila. On March 8th of 2012, Professor HUANG Diying from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences reported the diverse transitional giant fleas from Mesozoic of China in Nature, indicating that Saurophthirus is in fact a Cretaceous specialized flea. However, Strashila still remains an enigma. Strashila was originally reported in 1992 by a Russian palaeontologist. Some scholars believe that it greatly differs from the all known insects and it cannot be placed in any insect orders, while some even establish a new order to accommodate it, suggesting it is an ectoparasite on pterosaurs, or on feathered dinosaurs by some authors. The chelate hind legs were thought to be used for grasping the roots of dinosaur feathers. On February 20th of 2013, HUANG Diying and his group published an online paper titled “Amphibious flies and paedomorphism in the Jurassic period” in Nature. Based on 13 new specimens of Strashila discovered from the Middle Jurassic Jiulongshan Formation (approximately 165 million years) at Daohugou, Ningcheng County, Inner Mongolia, they put forward new interpretations on these insects, eventually solving the long-standing puzzling scientific problem. The newly found female individuals are totally different from the male: the hind legs of the former are not chelate, and the abdomen lacks lateral appendages, resembling a normal wingless fly and lacking the features of an ectoparasite. More importantly, a male individual has a large and broad forewing, which is evidently not a trait of ectoparasite. Therefore, Strashila are obviously by no means ectoparasites. Based on detailed morphological studies, Huang et al. suggest that, like the modern house flies and mosquitoes, Strashila is a member of Diptera, a relative of a primitive small group ？ Nymphomyiidae. Even though Strashila shares some characters with Nymphomyiidae, the males bearing very large wings, chelate hind legs and paired abdominal lateral appendages appear very different from modern nymphomyiids. A modern nymphomyiid, Nymphomyia walkeri, has a similar wing venation as that of Strashila. More interestingly, it has analogous lateral appendages on abdomen which is only found in males. N. walkeri has a special life habit: they mated beneath the water after emergence, shed their wings. For years only wingless individuals of N. walkeri are known, and they usually live in water, despite they can fly. Interestingly, they die in copula beneath the water. Probably like the modern nymphomyiids, after emergence and short-time flight, Strashila shed their wings andmated beneath the water. Thus, the winged Strashila are extremely rare. The mouthparts of Strashila are vestigial, suggesting that the adults do not feed and have an ephemeral life history. The chelate hind legs of males are probably sexually dimorphicused in male-male competition. The biological function of abdominal lateral lobes of N. walkeri remains unknown. Huang et al. indicate that Strashila has evident paedomorphism？the lateral lobes on abdomens are actually vestigial gills, and it represents the unique example of neoteny of fossil insects. Diying Huang*, André Nel, Chenyang Cai, Qibin Lin & Michael S. Engle, 2013: AmphibiousfliesandpaedomorphismintheJurassic period. Nature, DOI: 10.1038/nature11898.
Figure 1. Backscattered SEM image of Lenica spicules with core replaced by aluminosilicates and outer layer by pyrite (bright), with: A, Reconstruction of spicule structure; B, Interpretation of spicule evolution in sponges. Scale bar 200 μm. Sponges are among the most ancient of all animals, appearing in the fossil record at least 540 million years ago. Their early evolution is difficult to interpret, however, because their delicate skeletons do not fossilise easily. Ideas of early sponge evolution are currently based as much on molecular evidence from living species as they are from the fossil record, but research into the structure of the skeletons in early fossils is providing surprising insights. Most modern sponges fall into two easily separated groups: Silicea, with a skeleton of minute spicules made of opal (silica), and Calcarea, with spicules made of calcite. The secretion of these spicules is complex and varied, but in general, the two groups use different chemical and cellular processes to secrete their spicules, and it has been widely assumed that the two types of spicule evolved independently. This concept has been rejected by new work by a NIGPAS-based team: researcher Dr. Joseph P. Botting, with Dr. Lucy A. Muir, Professor Shuhai Xiao, Li Xiangfeng and Professor Jih-Pai Lin. The group has been working on early Cambrian (~520 million-year-old) sponges from the Hetang Biota of Anhui. In this paper, published in the journal Lethaia, they have studied the enigmatic sponge Lenica using Backscattered Electron Microscopy and elemental mapping. Lenica is classified as a protomonaxonid, a group of sponges with uncertain relationships to the modern classes of sponge, and which may have evolved earlier than the living groups. Lenica is unusual in having extremely large spicules, up to 10 cm long, and in the Hetang Biota they are preserved in a variety of ways. Although none of the spicules are preserved in pristine condition, it has been possible to obtain near-comprehensive information from the different preservational types. The results show that Lenica spicules consisted of a silica spicule with an axial filament (as in modern Silicea), surrounded by a second mineral layer that was probably calcium carbonate. There was also a thin, probably organic layer on the outside of the spicule, as seen in modern Calcarea. The spicules of Lenica therefore appear to consist of calcarean spicules around a core consisting of a silicean spicule. This shows that spicules are almost certainly shared between Calcarea and Silicea, supporting previous work by the first author but in contrast to standard views in modern biology. This has profound implications for the interpretation of the fossil record of sponges, and means that many early sponges should be assigned to primitive stem groups rather than living classes. Related information of this paper: Botting, J.P., Muir, L.A., Xiao, S., Li, X.-F. & Lin, J.-P. 2012. Evidence for spicule homology in calcareous and siliceous sponges: biminerallic spicules in Lenica sp. (Porifera; ?Protomonaxonida) of early Cambrian age (535-520 Ma) from South China. Lethaia 45, 463-475.
The Qinghai-Tibet Plateau represents the youngest plateau with complex tectonic evolution. In recent years, many models have been proposed based on those new advances on lithology, tectonics as well as geochemistry data. However, many models do not take into account the Upper Palaeozoic strata and palaeobiogeography. Dr. ZHANG Yichun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues recently made a review on the Permian stratigraphy, biostratigraphy and palaeobiogeography based on the previous studies and the authors’ fieldwork in Tibet for many years. This review reveals the following important aspects: ① The Qamdo Block, in palaeobiogeography, belongs to the Cathaysian Province during the whole Permian period whereas the Lhasa Block and the Qiangtang Block are ascribed to the South Transitional Zone during the Cisuralian, the Cimmerian Province during the Guadalupian and the Cathaysian Province during the Lopingian. This transition is considered to be triggered by both the northward drift of the Cimmerian continents and the background climatic amelioration after the Late Palaeozoic Ice Age. ② In palaeogeography, the Longmu Co-Shuanghu-Lancangjiang suture zone represents the main Palaeotethys suture with the Qamdo Block in the north lacking Late Carboniferous to Early Permian glacimarine deposits. ③ Three continental slices are recognized based on the depositional sequence and the faunal characteristics. They are the Lhasa-Tengchong-Sibumasu slice, the Qiangtang-Baoshan-Central Pamir slice and the South Pamir-Karakorum-South Afghanistan-Central Iran-Turkey slice respectively. The Lhasa-Tengchong-Sibumasu slice, lacking the Cisuralian rift-related magma, is considered to have close relationship with the Western Australia. The Qiangtang-Baoshan-Central Pamir slice and the South Pamir-Karakorum-South Afghanistan-Central Iran-Turkey slice are both considered to be separated actively from Gondwana diachronously. This paper will be published in Gondwana Research as the Focus Review style (Yi-chun Zhang, G.R.Shi, Shu-zhong Shen, 2012. A review of Permian stratigraphy, palaeobiogeography and palaeogeography of the Qinghai-Tibet Plateau. Gondwana Research, in press, doi: 10.1016/j.gr.2012.06.01)
Schematic Permian palaeogeographic reconstruction maps of northern Perigondwana and Palaeotethys with a focus on Tibetan blocks
Correlations of Permian sequences among the different blocks of the Qinghai-Tibet Plateau and adjacent blocks/areas
Cambrian Konservat Lagerst？tten such as the Chengjiang Biota and the Burgess Shale preserve far more biological and ecological information than do ordinary fossil deposits containing biomineralized organisms only. Yet in spite of the critical importance of Konservat Lagerst？tten for understanding the origin and development of modern-style ecosystems following the “Cambrian explosion”, the degree to which species diversity and composition vary between localities, and the environmental, taphonomic, ecological and evolutionary factors controlling this variation, are still poorly understood. Dr. ZHAO Fangchen from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues recently make an important progress in paleoecology of Cambrian Chengjiang Lagerst？tten. They intensively studied the fossil strata hosting the Lower Cambrian (Series 2, Stage 3) Chengjiang Biota (Maotianshan Shale Member, Yu'anshan Formation) occur throughout the eastern part of Yunnan Province, Southwest China. In their study, literature-based faunal inventories from 10 areas (representing 34 localities), together with 22,038 new specimens collected at three localities from three of the 10 areas, were analyzed quantitatively to assess large-scale spatial variation in taxonomic diversity and composition. These analyses show substantial covariation between local paleoenvironmental settings and species diversity, and suggest the presence of three general taphofacies in the Maotianshan Shale Member. Their study shows that the Chengjiang Biota lends itself very well to high resolution characterization of spatial variation in taxonomic diversity, faunal composition and fossil preservation. Furthermore, the Chengjiang Biota may provide a unique opportunity to assess the roles of environmental factors, taphonomy and ecological controls on species diversity at local to regional spatial scales. This work has been recently published in Palaeogeography, Palaeoclimatology, Palaeoecology (Fangchen Zhao, Shixue Hu, Jean-Bernard Caron, Maoyan Zhu, Zongjun Yin, Miao Lu, 2012. Spatial variation in the diversity and composition of the Lower Cambrian (Series 2, Stage 3) Chengjiang Biota, Southwest China, Palaeogeography. Palaeoclimatology. Palaeoecology, Volumes 346-347, 54-65. http://dx.doi.org/10.1016/j.palaeo.2012.05.021).
Representative fossils from the lower Cambrian Yu'anshan Formation, Maotianshan Member, showing the preservational characteristics of the three general taphofacies present in Eastern Yunnan.
Polished slabs and schematic diagrams of typical sedimentary facies.
Simplified storm event model showing the relative positions of different taphofacies and ecological spaces of the Chengjiang Biota.
