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.
Mass extinction can severely disturb not only the global ecosystem and its ecological foundation, but also the palaeobiogeographical framework severely. Research on palaeobiogeography of the survival and recovery intervals is significant in understanding macro-evolutionary processes after mass extinction. Dr. HUANG Bing and Prof. RONG Jiayu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), with Prof. Robin Cocks (Natural History Museum, UK), have recently published a study in the journal Palaeogeography, Palaeoclimatology, Palaeoecology. The paper summarized and revised published information on the recovery of early and late Rhuddanian brachiopod faunas. The global dataset consists of 137 occurrences, 72 genera, and 13 localities of Early Rhuddanian (survival interval), and 271 occurrences, 91 genera, and 26 localities of the late Rhuddanian (early recovery interval). The data are analyzed using cluster analysis, nonmetric multidimensional scaling, and minimum spanning tree. The results display palaeolatitudinal distribution patterns for brachiopods during their survival and recovery. Frequency analysis of the data indicates that cosmopolitan taxa before the mass extinction decreased in their post-extinction distribution. The survivors were mostly confined to one palaeoplate or even one locality in the survival interval, but expanded progressively in the subsequent recovery period. Paper reference: Huang Bing; Rong Jiayu; Cocks L. Robin M. 2012. Global palaeobiogeographical patterns in brachiopods from survival to recovery after the end-Ordovician mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 317, 196-205.
Giant fleas from the Middle Jurassic of Daohugou, China Professor HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues make an important progress in Palaeoentomology recently. A paper entitled “Diverse transitional giant fleas from the Mesozoic era of China”has been published online in Nature on the 29th, February. Fleas, including circa 2500 recent species or subspecies, are one of the dramatically specialized group of insect lineages, with reduction of wings, laterally-flattened body, and small size (usually 1-3 mm long). Fleas are ectoparasiticinsects specialized for feeding on the blood of mammals (including human beings) or birds. Fleas are difficult preserved as fossils like other ectoparasitic insects. Definitive fossil evidence of fleas has been largely confined to Cenozoic amber, and they are of extant forms. Therefore, the evidence suggesting the origin and early evolution of fleas has been lacking.Hitherto, only one record of fossil flea Tarwinia has been described from the Late Cretaceous of Australia (ca. 120 Ma). However, its affinity remains highly controversy. In recent years, HUANG Diying has found several giant flea from the Middle Jurassic Daohugou biota (ca. 165 Ma) at Ningcheng Couty, Inner Mongolia and and the Early Cretaceous Jehol biota (ca. 125 Ma) at Beipiao City, Liaoning Province of China, which provides new insights into the origin and early evolution of fleas and the adaption of hosts. This find traced back the earliest occurrence of fleas (Order Siphonaptera) at least for 40 million years. These Mesozoic fleas are of great body sizes, approximately15 mm in length, and some longer than 20 mm. As the extant fleas, the ancient females are larger than males. For example, a flea species from Daohougou is 14 mm for female and only 8 mm for male. They are wingless insects, but more or less dorso-ventrally flattened, their antennae are short and compact with more antennal segments (16-19 segments) than extant ones (11 segments); they have a very long piercing siphonate mouthparts, elongate legs armed with various ctenidia, but its hind legs are not jumping type as in Recent fleas, abdomen covered numerous posteriorly-directed setae; male genitalia large and exposed. New Mesozoic fleas with very long piercing mouthparts suggest a resemblance to some Mesozoic siphonate mecopteran, which supports the hypothesis that fleas are derived from Mecoptera. By contrast the Tarwinia, the new Middle Jurassic and Early Cretaceous fleas armed with various ctenidia on legs and numerous posteriorly-directed setae on abdomen, indicating an adaption to hosts with hairs or furs. From the same period, a number of mammals have been described, but they are normally of small body size. If they are hosts for ancient fleas, the fleas should have been hidden in their nests. Nevertheless, the long siphon of fleas is obviously able to pierce the skin of feathered dinosaurs, so this is also a possibility. In addition, a peculiar insect from the Early Cretaceous of Russia, Saurophthirus, was suggested as an ectoparasitic insect for pterosaur. We suggest it is also a specialized flea. The above evidence indicates Mesozoic fleas have already display obvious specialization for adapting to different hosts. This research was financially supported by National Natural Science Foundation of China, Ministry of Science and Technology of PRC, Chinese Academy of Sciences, and State Key Laboratory of Palaeobiology and Stratigraphy. References: Huang, D., Engel, M. S., Cai, C., Wu, H. & Nel, A. Nature http://dx.doi.org/10.1038/nature10839 (2012).
Reconstruction of actual site 3 of a peat-forming forest of earliest Permian age that was preserved by a volcanic ash-fall near Wuda, Inner Mongolia, China. An ancient forest preserved in volcanic ash from Inner Mongolia, China provides us a fantastic window to see the vegetational community 298 million years ago. The study by WANG Jun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and colleagues discovered an Early Permian forest buried in volcanic ash and preserved in a way much like the Roman city of Pompeii. The researchers were able to use the actual location of individual plants to reconstruct 1137 m2 of the forest, which is large enough for an investigation of the floral ecology. Six plant groups consist of the flora, with tree ferns forming a lower canopy and either Cordaites, a conifer, or Sigillaria, a lycopsid, appear as taller trees. Landscape heterogenity is apparent, including one site where Noeggerathiales, an extinct spore-bearing group of small trees, are dominant. The researchers also discovered significant differences in the distribution and ecology of ancient plants from what is now China and East Asia and those from what is now Europe and North America. The preserved forest is from a period marked by oscillating climatic variations, and it is suggested that studying it would help researchers understand not just ancient ecosystems but also changes to modern global vegetation. This work has been recently published in PNAS (Jun Wang, Hermann W. Pfefferkorn, Yi Zhang, and Zhuo Feng, Permian vegetational Pompeii from Inner Mongolia and its implications for landscape paleoecology and paleobiogeography of Cathaysia. PNAS 2012 ; published ahead of print February 21, 2012, doi:10.1073/pnas.1115076109) .
Reconstruction of the peat-forming forest of earliest Permian age preserved by a volcanic ash-fall that buried stems, broke off twigs, toppled trees, and preserved the forest at site 1 near Wuda, Inner Mongolia, China
