Abundant rudist bivalves have been reported from the Yigeziya Formation, most of them were considered as endemic taxa that were restricted to central Asia including Tajik, Fergana, Alai and Tarim basins. During Cretaceous to Paleogene, a shallow epicontinental sea extended across Eurasia from the Mediterranean Tethys to the southwestern Tarim Basin, and its eastern extremity being referred to as the Tarim Sea, which was commonly regarded as a branch of the Neotethys. During Late Cretaceous, two distinct transgressive events have been identified in Tarim Sea: the first is represented by the deposition of early Cenomanian to Turonian Kukebai Formation, and the second formed the Campanian to early Maastrichtian Yigeziya Formation. Abundant rudist bivalves have been reported from the Yigeziya Formation, most of them were considered as endemic taxa that were restricted to central Asia including Tajik, Fergana, Alai and Tarim basins. Biradiolites minor Pojarkova, described by Lan and Wei (1995) from the middle member of the Yigeziya Formation, is characterized by the glabrous outer shell layer except for four salient ridges on the shell margin of the right valve. This feature is inconsistent with the genus Biradiolites d’Orbigny which is normally ornamented with strongly protruding longitudinal ridges over the whole right valve. Recently, Dr. RAO Xin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and her colleagues re-studied the species B. minor based on the published and new specimens, transferred it to the genus Glabrobournonia according to the taxonomic re-examination. Glabrobournonia is a genus of radiolitids characterized by indented radial bands, salient ridges on the shell margins and absence of fine ribs on the surface of the right valve. Apart from southwestern Tarim Basin, Glabrobournonia minor (Pojarkova) has also been recorded from the late Campanian of Fergana and Alai basins. The central Asian, late Campanian to early Maastrichtian G. minor differs from the late Campanian to Maastrichtian, eastern Arabian type species Glabrobournonia arabica Morris and Skelton in the flat left valve and an additional fourth ridge on the junction of the dorsal and posterior sides of the right valve. Biradiolites ingens (Des Moulins) could be the direct ancestor of Glabrobournonia. The paleogeographic distribution of Glabrobournonia suggests that this genus dispersed to central Asia from the late Campanian time, becoming widely distributed in the eastern Tethyan region rather than endemic to eastern Arabia. Correspondingly, specimens belonging to Gyropleura yielded from the same bed as G. minor in southwestern Tarim Basin, are similar to the specimens which were attributed to the eastern Arabian Gyropleura sp.; Campanian to early Maastrichtian Osculigera specimens described from the Yigeziya Formation are comparable with those known from the Campanian–Maastrichtian of Iran, Afghanistan and eastern Arabia. The similarity of the rudist assemblages between central Asia and eastern Arabia suggests a faunal connection and affinity between the north and south margins of the eastern Tethyan realm during Campanian to early Maastrichtian times. This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, the National Natural Science Foundation of China, and the State Key Laboratory of Palaeobiology and Stratigraphy, Chinese Academy of Sciences. Reference: X. Rao, P. W. Skelton, S. Sano et al., Taxonomy and paleobiogeographic implication of Glabrobournonia Morris and Skelton (Hippuritida, Radiolitidae) from the Late Cretaceous Yigeziya Formation, southwestern Tarim Basin, Palaeoworld, https://doi.org/10.1016/j.palwor.2022.05.003. Fig. 1. (a) Map of the southwestern Tarim Basin and adjacent basins bearing Late Cretaceous rudists. (b) Geologic map showing the fossil locality in southwestern Tarim Basin. (c) Stratigraphic column of the Yigeziya section and the occurrence of Glabrobournonia minor within the section. Fig. 2. Glabrobournonia minor (Pojarkova) from the Yigeziya Formation of the Yingjisha County, southwestern Tarim Basin. Scale bar represents 10 mm. Fig. 3. Paleogeographic map of late Campanian showing the reconstructed situations of the fossil localities bearing Glabrobournonia (base map after Scotese, 2014). Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Resource pulses, occasional events of ephemeral resource superabundance, represent a fundamental mechanism by which energy, nutrients, and biomass are transported across ecotones. They are widespread in extant ecosystems; however, little is known about their deep-time record. Resource pulses, occasional events of ephemeral resource superabundance, represent a fundamental mechanism by which energy, nutrients, and biomass are transported across ecotones. They are widespread in extant ecosystems; however, little is known about their deep-time record. Recently, ZHANG Qianqi, a PhD student from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Profs. WANG Bo and ZHANG Haichun, in collaboration with other researchers carried out a detailed investigation of early Mesozoic terrestrial strata in several regions in southern China. The researchers discovered abundant marine and terrestrial animal and plant fossils in the Lower Jurassic Shiti Formation in the Xiwan Basin of Hezhou City, Guangxi Province, China. Researchers report the earliest-known mayfly swarm from the Early Jurassic Xiwan biota of southern China, and the results were published in the journals Geology and Historical Biology. The Mesozoic study in the Xiwan Basin has a long history, and both Profs. SZE Hsing-Chien and ZHOU Zhiyan had ever studied the plant fossils from Xiwan, among which plenty of insect fossils from the Shitian Formation were reported by Prof. LIN Qibin. "We recently found abundant new insects, plants, and shark egg capsules from a new fossil locality. In view of the abundance of the diverse insects and plants, we propose that the fossil assemblage in the lower unit of the Shiti Formation be named the Xiwan biota, which is among the richest Jurassic biotas in China", ZHANG Qianqi says. This research team found one fossil layer with hundreds of mayflies in the lower unit of the Shiti Formation. These mayflies were classified as a new taxon, Jurassephemera zhangi Zhang et al. (2022), which is assigned to the extinct family Sharephemeridae, a stem group mayflies in terms of taxonomic position. This is the first discovery of the mayfly family in China, and is the best preserved fossil of the family. "We measured the orientations of 381 mayflies and found that these mayflies do not show any obvious directionality, although the rose diagram suggests a south westerly trend perhaps reflecting the effect of a slight movement of the bottom water after accumulation of the carcasses", says ZHANG. Furthermore, all the mayflies are complete with body, appendages, and wings attached, which, when taken with the above, indicates that the mayflies were not transported any significant distance in the water after death and were buried in a low-energy preservational environment. Extant mayflies spend most of their life in the aquatic environment as nymphs, and the adults commonly live from as little as 1–2 hours to a few days. During their short adult phase, the males form dense aggregations, and the females must find mating partners while flying in and through large swarms, wherein they copulate and ultimately locate a suitable place to deposit eggs. Mating-swarm behavior was previously known only in crown mayflies; however, our find reveals that such complex behaviors were already well established in stem-group mayflies by the Early Jurassic. "And this finding represents the earliest evidence of mating-swarm behavior in insects", ZHANG says. Using elemental energy spectroscopy and Raman component analysis, the results show that the outermost layer of the fossils of the Xiwan biota is mainly iron oxides and clay mineral residues, but the surface composition of the fossils is still dominated by carbon elements. The researchers conclude that the iron oxide covering of the fossil surface was formed during the diagenetic process later and likely formed during the weathering process. Aquatic insects play an important role in aquatic food webs, acting as consumers of aquatic plants and animals, and they are in turn consumed by fish and other predators. But aquatic insects can also be important parts of food webs on land when they emerge as adults from the water and fly to disperse and find mates. In addition to providing food bonanzas for predators, emerging insects can also have a fertilizing effect on plant communities next to lakes and streams when they die and decompose. This study shows that some Jurassic mayflies emerged all at once in large swarms, which is a “pulse” of insects moving from the water to land, probably resulting in massive ecosystem fluxes in waterside habitats with impacts on basic ecology and biogeochemical cycling. Such a mechanism that can play a substantial role in nutrient transport from aquatic ecosystems to surrounding terrestrial ecosystems, while this aquatic-terrestrial ecosystem linkage may be a key novelty in Mesozoic lacustrine ecosystems. "Therefore, our finding highlights the underappreciated ecological significance of insects in short-lived feeding bonanzas and mass mortalities in deep-time lacustrine ecosystems." ZHANG added. This research was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Zhang Qianqi, Wang Bo*, Zheng Daran, Li Jiahao, Wang Xueheng, Jarzembowski E.A., Xu Chunpeng, Li Ting, Zhang Haichun, Engel M.S. 2022. Mayflies as resource pulses in Jurassic lacustrine ecosystems. Geology. https://doi.org/10.1130/G50055.1. Zhang Qianqi*, Zheng Daran, Jarzembowski E.A., Wang Xueheng, Li Jiahao, Engel M.S. 2022. The first Sharephemeridae (Insecta: Ephemeroptera) from the Jurassic Shiti Formation of South China. Historical Biology. https://doi.org/10.1080/08912963.2022.2077649. Figure 1: Three pieces of fossil surface with mayfly swarms from the Shiti Formation in southern China. All are the same scale and orientation. Figure 2: Sedimentology (A–D) and taphonomy (E–L) of the fossil-bearing layer from the Shiti Formation in southern China. Figure 3: Reconstruction of the Early Jurassic ecosystem of the Xiwan Basin (designed by YANG Dinghua, NIGPAS).
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
What would happen in the near future with continued global warming? What environmental conditions would the life on Earth most likely confront? The episodes of climate changes in the Earth’s deep past, similar to the current global warming, may provide valuable clues to these questions. What would happen in the near future with continued global warming? What environmental conditions would the life on Earth most likely confront? The episodes of climate changes in the Earth’s deep past, similar to the current global warming, may provide valuable clues to these questions. A recent study led by scientists from China, U.S., and New Zealand reveals that an abrupt warming linked to massive carbon emission during an icehouse climate state caused approximately 20% of anoxic areal extent of the seafloor, and significant biodiversity drop. The finding was published by the Proceedings of the National Academy of Sciences of the United States of America on May 2, 2022. As is known, we are currently living under the Cenozoic icehouse climate that has started since 34 Myr ago. However, global temperature rises rapidly under this icehouse over a couple of centuries, in tandem with accelerated ablation of polar glaciers, rising sea-level, and aggravating marine de-oxygenation, and undoubtedly leading to a significant drop in biodiversity. Where would the global warming lead us to in the future? There are substantial uncertainties regarding the modeling results based on current observations, which drive the current focus on understanding past episodes of carbon emission and ocean deoxygenation, particularly under an icehouse climate state. The Late Paleozoic Ice Age (LPIA, between 360 and 280 million years ago) is the longest-lived and the only icehouse that recorded the transition from icehouse to greenhouse climate states since the occurrence of advanced plants and terrestrial ecosystem. The LPIA is also the only geological period that is featured by low atmospheric CO2 and high O2 concentrations, highly comparable to those of the modern day. It is, therefore, critical to study carbon emissions and their consequences during the LPIA for better understanding the processes and feedbacks of the icehouse Earth system, and thus for more precisely predicting the future environmental and biodiversity changes. A international research team led by Dr. CHEN Jitao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Dr. WANG Xiangdong from the Nanjing University, and Dr. Isabel P. Montanez from the University of California, Davis studied the Carboniferous strata from the southern China for over 10 years, with respect to sedimentology, stratigraphy, paleontology, and geochemistry. The Naqing and Narao sections from the Luodian region, Guizhou Province crop out continuous Carboniferous carbonate successions that register geochemical signal of sea water. Scientists collected samples by every 20 cm for over 40-m-thick strata from the two sections and carried out carbon and uranium isotopes to explore the global carbon cycling and marine anoxia. "We utilized global carbon cycle model (LOSCAR) and paleo carbon dioxide concentrations to simulate a total amount of 9,000 Gt C emitted over 300 kyr, causing an increase in sea-surface temperature by ~4℃", CHEN says. "We also modelled an increase in areal extent of the anoxic seafloor from 4% to 22%, causing a dramatic decrease in biodiversity" CHEN Added, "and finally, we performed climate model simulations using the fully coupled Community Earth System model (CESM) to explore the potential mechanisms for the marine anoxia, which are linked to enhanced thermocline stratification and increased nutrient fluxes during the warming." The study further finds that warming-induced marine anoxia may be more pronounced in a glaciated than in an unglaciated period. Reference: Chen, J.T., Montanez, I.P., Zhang, S., Isson, T.T., Macarewich, S.I., Planavsky, N.J., Zhang, F., Rauzi, S., Daviau, K., Yao, L., Qi, Y.P., Wang, Y., Fan, J.X., Poulsen, C.J. Anbar, A.D., Shen, S.Z., Wang, X.D., 2022. Marine anoxia linked to abrupt global warming during Earth’s penultimate icehouse, PNAS, https://doi.org/10.1073/pnas.2115231119. Fig. 1. An abrupt global warming occurred at ~304 Ma under the Carboniferous icehouse climate state, consistent with doubling of atmospheric carbon dioxide, significant negative excursion in carbon isotopes, sea-surface temperature increase, and drop in biodiversity. Fig. 2. Carbon and uranium isotopes recorded in the Naqing section, Guizhou Province, southern China, showing remarkable negative excursions across the Kasimovian-Gzhelian boundary. Modeling results suggest a distinct perturbation in global carbon cycle and an increase in marine anoxia. Fig. 3. Comparison between the KGB warming event during the late Carboniferous icehouse and greenhouse C-perturbation events over the last 300 Myr, indicating that the KGB warming had a more extreme impact on the marine redox landscape relative to its rate of C injection and SST increase than the other events. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Assembly of Gondwana commenced in the Neoproterozoic with final disassembly of the supercontinent completed by the Cretaceous. The configuration of major continental blocks (e.g., India, Australia, East Antarctica, and Africa) of Gondwana has been well reconstructed. However, paleopositions of some small continental fragments along the periphery of Gondwana are still in controversy. Assembly of Gondwana commenced in the Neoproterozoic with final disassembly of the supercontinent completed by the Cretaceous. The configuration of major continental blocks (e.g., India, Australia, East Antarctica, and Africa) of Gondwana has been well reconstructed. However, paleopositions of some small continental fragments along the periphery of Gondwana are still in controversy. The Baoshan, Tengchong, Lhasa, South Qiangtang, and Sibumasu terranes were located along the northern margin of Gondwana before late Early Permian rifting. A substantial amount of work has been carried out, aiming at reconstructing the paleopositions of these terranes from various disciplines such as sedimentary provenance, paleomagnetism, and paleobiogeography. These studies led to various paleogeographic models of northeastern Gondwana. Recently, a paleogeographic study based on detrital zircon U-Pb ages and Hf isotopic values from Paleozoic strata of northeastern Gondwana, which is conducted by GAO Biao, his advisor Prof. CHEN Jitao, and Prof. QIE Wenkun from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with the scientist Prof. WANG Xiangdong from Nanjing University. Primary component analysis (PCA) was used to visualize the relative relationship between these terranes and East Gondwana, in addition with the glacier distribution pattern on northeastern Gondwana in the late Paleozoic. The research achievements were published in the international journal Sedimentary Geology. Based on a total of 8209 detrital zircon U-Pb ages and 1606 zircon Hf isotopic values from Paleozoic strata of northeastern Gondwana, a new paleogeographic model has been reconstructed. It indicates that the South Qiangtang, Baoshan, and part of Sibumasu were outboard of the northern margin of Indian Gondwana during the Paleozoic, whereas the Lhasa and Sumatra terranes were located along the northern margin of Australia. Based on provenance shifts of late Paleozoic glaciogenic sedimentary rocks in northeastern Gondwana, two main ice sheets are hypothesized to have developed during the late Paleozoic. This study further confirms the model of a multicenter glacier distribution pattern on Gondwana during the late Paleozoic ice age from a perspective of provenance. The research is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Second Tibetan Plateau Scientific Expedition and Researh Program. This is a contribution to IGCP 700 and DDE (Deep-time Digital Earth) projects. Reference: Gao, B.*, Chen, J.T.*, Qie, W.K., Wang, X.D., 2022. Revisiting the paleogeographic framework of northeastern Gondwana in the late Paleozoic: implications from detrital zircon analysis. Sedimentary Geology. Available online 11 April 2022. https://doi.org/10.1016/j.sedgeo.2022.106144. Schematic geological map of Southeast Asia and detrital zircon samples locations Primary component analysis (PCA) of detrital zircon characteristic age population
Reconstruction of northeastern Gondwana with regional ice centers during the late Paleozoic ice age Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
The rapid appearance of major animal groups and complex marine communities during the Cambrian explosion is recorded in large part in Burgess Shale-type lagerst？tten. Nevertheless, most of the well-known Cambrian lagerst？tten are restricted to a few terranes, with most of them occurring in South China (Epoch 2) or Laurentia (Miaolingian). The large tempo-spatial discrepancy of distribution of the soft-bodied fossil lagerst？tten limits our understanding of the Cambrian explosion of animals on earth. The rapid appearance of major animal groups and complex marine communities during the Cambrian explosion is recorded in large part in Burgess Shale-type lagerstatten. Nevertheless, most of the well-known Cambrian lagerstatten are restricted to a few terranes, with most of them occurring in South China (Epoch 2) or Laurentia (Miaolingian). The large tempo-spatial discrepancy of distribution of the soft-bodied fossil lagerstatten limits our understanding of the Cambrian explosion of animals on earth. Named the Linyi Lagerstatte (ca. 504 mya), a new middle Cambrian lagerstatte from the Zhangxia Formation in Shandong Province, North China, provides a new window into the morphological disparity, community structure, and paleogeographic distribution of marine faunas following the Cambrian explosion. A research team from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) reports online April 5 in National Science Review. The limited known spatial distribution of Cambrian lagerstatten thus underscores the importance of the newly discovered Miaolingian Linyi Lagerstatte. The new assemblage contains a variety of well-preserved soft-bodied fossils, among which the non-trilobite arthropods, particularly the mollisoniids and radiodonts, are the most important groups. The Linyi Lagerstatte is remarkable for its excellent preservation of arthropod limbs, eyes, and guts, these well-preserved fossils promise to yield new anatomical data bearing on the early evolution of animals. "The close similarity in taxonomy between the Linyi Lagerstatte of North China and those of Laurentian lagerstatten suggests that North China may have provided a biogeographic link between East Gondwana and Laurentia" Prof. ZHAO Fangchen says. North China is now an important region for investigating the early evolution of middle Cambrian animals, and its Miaolingian deposits have great potential for yielding additional exceptional biotas. Since the discovery of the Chengjiang biota in 1984, South China has gradually become the principal area for the study of early Cambrian Lagerstatte. The discovery of the Linyi Lagerstatte may also open a new chapter in the study of middle Cambrian BST deposits in North China. Reference: Sun, Z.X., Zhao, F.C.*, Zeng, H., Luo, C., Van Iten, H., Zhu, M.Y., 2022. The middle Cambrian Linyi Lagerstatte from the North China Craton: a new window on the Cambrian evolutionary fauna. National Science Review, https://doi.org/10.1093/nsr/nwac069. Fig. 1. Spatial and temporal distribution and taxonomic diversity of 16 major Cambrian lagerst？tten, and the position of the Linyi Lagerstatte Fig. 2. Representative fossils from the Linyi Lagerstatte. A. Thelxiope spinosa; B. Mollisonia symmetrica; C. Monospecific cluster of the sponge Diagoniella sp; D. Thelxiope tangi sp. nov; E, Oral cone of ; Cordaticaris striatus F, Changqingia puteata; G, Worm-like animal; H, Frontal appendages of Cordaticaris striatus; I. Frontal appendage of an amplectobeluid Fig. 3. Biogeographic comparisons of Cambrian lagerstatten and the position of the Linyi Lagerstatte. (A) Ordination plot of non-metric multidimensional scaling (nMDS) analysis. (B) Cluster analysis. (C) Bipartite network analysis Fig. 4. Life on the platform margin of the Miaolingian sea, North China. Based on data from the Linyi Lagerstatte. Drawing by Dinghua Yang Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Insects are today the most diverse group of organisms on Earth and are responsible for a wide array of ecosystem services. They are important components in modern terrestrial ecosystems, and commonly influence ecosystem cycling of carbon and nutrients by modulating the quality and quantity of resources. Understanding the evolution of insects and their roles in deep-time terrestrial ecosystems are key to decoding the rise of modern terrestrial ecosystems. Insects are today the most diverse group of organisms on Earth and are responsible for a wide array of ecosystem services. They are important components in modern terrestrial ecosystems, and commonly influence ecosystem cycling of carbon and nutrients by modulating the quality and quantity of resources. Understanding the evolution of insects and their roles in deep-time terrestrial ecosystems are key to decoding the rise of modern terrestrial ecosystems. Recently, Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), synthesized the fossil record of Mesozoic holometabolous insects and explored fossil evidence for the evolution of key ecological interactions in terrestrial environments. This study was published in Trends in Ecology & Evolution on March 11, 2022. The Mesozoic is a key era for the rise of the modern insect fauna. Among the most important evolutionary events in Mesozoic insects are the radiation of holometabolous insects, the origin of eusocial and parasitoid insects, diversification of pollinating insects, and development of advanced mimicry and camouflage. These events are closely associated with the diversification of insect ecological behaviors and colonization of new ecospaces. During the past two decades, there has been enormous progress in our understanding of these events due to the discovery of new fossils and lagerst？tten, which also provide robust evidence for insect-plant and insect-insect ecological interactions. The fossil record of insects contains larger geographic, temporal and taxonomic gaps than the fossil record of vertebrates and of some marine invertebrates. In fact, more than half of all described insect occurrences in the fossil record come from major Lagerst？tten. Due to the depauperate and uneven fossil record, the estimates of insect paleodiversity is mainly restricted to higher-level taxa and the detailed ecological response of insects to several key environmental events is still unclear. Furthermore, there is a preservational bias toward medium-size insects for compression–impression fossil deposits. Although amber can preserve minute insects, before the widespread occurrence of amber with insect inclusions, the fossils mainly showed the patterns of diversity of medium-size insects. This reminds us that the currently-known evolutionary history of some insect interactions may be incomplete. Recent work on the paleobiology, phylogenetics, taphonomy, and other related fields has facilitated novel understanding of important evolutionary events in Mesozoic entomology and opened up new perspectives. These events are closely associated with the diversification of insect ecological behaviors and colonization of new ecological niches entailing closer associations with various plants and animals. Mesozoic insects no doubt played a key ecological role in reconstructing and maintaining terrestrial ecosystems. Nonetheless, the potential ecological roles of these insects are not yet fully explored and their importance warrants more detailed paleoecological study. Many extant terrestrial insects are undergoing dramatic declines in abundance and diversity largely due to anthropogenic deforestation and global warming. Although the phylogenetic landscape was distinctly different in the geological past from that of the present day, a greater understanding of the history of insects could make it possible to formulate broader ecological predictions and policies for the future. "We need to understand particularly their pioneering ecological roles in deep-time terrestrial ecosystems and their response to extreme environmental events." Prof. WANG says, "in particular, paleobiological research provides empirical evidence of how insect communities were shaped by natural climatic events of the past, especially global warming in the Mesozoic." Examining changes in taxonomic diversity, morphological disparity, and ecological shift of insects in concert can provide a more comprehensive view of the evolutionary trajectory and could illuminate underlying evolutionary processes without resort to ‘just-so’ stories. Such studies as discussed above may help to mitigate future changes in insect diversity and abundance faced with accelerating global environmental change. This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, and the National Natural Science Foundation of China. Reference: Wang Bo, Xu Chunpeng, Jarzembowski E.A. (2022) Ecological radiations of insects in the Mesozoic. Trends in Ecology & Evolution, https://doi.org/10.1016/j.tree.2022.02.007.
Figure 1. The origins of some key insects and plants according to fossil evidence.
Figure 2. Geological range of insect mimesis, debris-carrying camouflage, and eusocial behavior.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Inclusions in amber can preserve organisms’ organs, tissues and cells in high fidelity, and are known as “exceptionally preserved” fossils. Inclusions in amber can preserve organisms’ organs, tissues and cells in high fidelity, and are known as “exceptionally preserved” fossils. Amber inclusions are commonly thought to be mummified remains or hollow moulds, and the body cavities and walls of the moulds are mainly thought to be filled with carbonaceous material. However, this pattern may not apply to all amber inclusions. Recently, JIANG Hui, the postgraduate supervised by Profs. WANG Bo and ZHANG Haichun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, along with their collaborators from University of Bonn, Cornell College and other institutions, have proved the widespread mineralization of amber insects in Kachin amber and further reconstructed the taphonomic pathways of mineralized inclusions in amber. The study was published in Geobiology on Feb. 25. By opening a few pieces of amber and applying a variety of techniques, the researchers discovered calcification and silicification of insects in amber, which are very rare processes in the insect fossil record. The analysis showed that the mineralized insects consisted of calcite, microcrystalline quartz and macrocrystalline quartz. These minerals occupied the positions of numerous tissues and substrates, occurring as replacement minerals in organic structures and void-filling cements in cavities within the insects’ bodies. "The preservation of mineralized insects is incredible, with complete calcified compound eyes, exquisite cuticle structures, as well as skin sensillae," said JIANG Hui. In the silicified specimens, fine body structures such as the trachea and fibrous structures were preserved in the form of microcrystalline quartz, and the body cavities looked like agate geodes. Insects generally do not have biomineralized tissues made of silica or calcium carbonate. "The chemical species leading to silicification and calcification of the Kachin insects were considered to come from two sources: decomposition of their tissues in response to microbial respiration and fluid from the surrounding environment," said Prof. WANG Bo. "Homogeneous minerals in amber inclusions are also precipitated in cracks in the amber matrix surrounding the inclusions. This suggests that the fluid carrying the mineralized reaction species entered the amber along the cracks and then contacted the inclusions," said Prof. ZHANG Haichun. The pyrite in the silicified insect leg may be evidence of microbial sulfate reduction. Other processes like iron reduction and methanogenesis may have also contributed to calcification and silicification. All of these processes generate HCO3- that can react with dissolved Ca2+ to precipitate as calcite. The dissolved silica may have come from volcanic vents, hydrothermal springs, or clay diagenesis. Kachin amber occurs with volcaniclastic rock, and was preserved in shallow, nearshore depositional environments, where evaporation of seawater may have affected the dissolved silica levels. Hematite and goethite form in oxidative environments, and they may suggest diagenetic pore fluids that developed during tectonism or ground water that conduced to terrestrial weathering. The presence of organic matter in inclusions may provide reactive interfaces to promote nucleation of silica and calcite films. This new discovery indicates that mineralization played an important role in the preservation of fossils in Kachin amber, and mineralization in amber is more widespread than commonly thought. The results demonstrate that resin and amber are not closed systems. Fluids (e.g., sediment pore water, diagenetic fluid, and ground water) at various burial stages may interact with amber throughout its geologic history and affect the preservational quality and fidelity of amber inclusions.
Fig. 1 Calcified and silicified grasshopper. (Image by NIGPAS)
Fig. 2 Taphonomic model for mineralized insects in Kachin amber. (Image by NIGPAS)
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Silurian (Telychian) conodont distribution on the Yangtze Platform of South China is quantitatively studied for the first time. Silurian (Telychian) conodont distribution on the Yangtze Platform of South China is quantitatively studied for the first time. Conodonts are of significant importance for global biostratigraphic correlation of strata containing Palaeozoic and Triassic marine faunas but this biostratigraphic utility can be complicated by their depth-controlled distribution. Temporal and spatial distribution patterns of conodonts have attracted increasing attention during the past six decades. Palaeoecological distribution of Silurian conodonts has been widely discussed, but knowledge of conodont associations in the Llandovery is uneven. Previous studies demonstrated that Telychian conodont distributions were related to the associated palaeoenvironments, therefore hindering global correlation of conodont zonations. Diverse Telychian (Llandovery Series, Silurian System) conodont faunas have been documented from the South China Palaeoplate. YAN Guanzhou, a Ph.D. candidate in the Early Paleozoic team of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Prof. WU Rongchang, collaborated with members of the group and Dr. Ian G. Percival from Australia, based on data from six selected sections in the Yangtze Platform, the spatial distribution of the Telychian conodont associations is investigated in detail by use of multivariate statistical methods. The results of this study were recently published in the Journal of Asian Earth Sciences. On the basis of statistical analysis, two Telychian conodont biofacies can be observed in South China: the Dapsilodus-Decoriconus Biofacies which is restricted to deep-water environments, and the Apsidognathus-Galerodus Biofacies which is indicative of shallower water environments. One regression and two transgressions are deduced from relative abundance patterns of characteristic conodont taxa comprising these biofacies. Vertical changes of conodont biofacies in the Baizitian and Xuanhe sections permit the recognition of transgressive–regressive patterns which are closely similar to published sea-level curves for the Early Silurian. Pterospathodus eopennatus Therefore, it is argued that vertical variations in abundance of specific Silurian conodont taxa can be used as proxies for inferring major changes in sea-level. This research was supported by the National Natural Science Foundation of China and the Strategic Priority Research Program of the Chinese Academy of Sciences. Ian Percival publishes with permission of the Executive Director of the Geological Survey of New South Wales. Reference: Yan Guanzhou, Wu Rongchang*, Huang Bing, Percival I.G, Gong Fangyi, Wei Xin & Li Lixia. 2021. Llandovery (Silurian) conodont biofacies on the Yangtze Platform of South China and their palaeoenvironmental implications. Journal of Asian Earth Sciences, 225(2): 105044. https://doi.org/10.1016/j.jseaes.2021.105044. Scatter-plot of correspondence analysis (COA) showing the analysed Telychian (Llandovery, Silurian) sections and taxa (genera). A. Network diagram based on species-level data shows an overview of the conodont species in the Pterospathodus eopennatus Zone of the selected sections. B. Cluster analysis of the conodont species in the Pterospathodus eopennatus Zone of the selected sections.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
The Lower Devonian deposits develop well and are widely distributed in the South China Plate, Its Early Devonian flora shows high endemism especially at the generic level. The Posongchong flora from the Lower Devonian of Yunnan, as a representative working area, has a total of 28 genera and 37 species of plants and over 70% genera are endemic. Several regional floras other than Yunnan have been discovered from southern China, as Pingyipu of Jiangyou, Yangling of Chongyi, and Shiqiao of Cangwu. The Lower Devonian deposits develop well and are widely distributed in the South China Plate, Its Early Devonian flora shows high endemism especially at the generic level. The Posongchong flora from the Lower Devonian of Yunnan, as a representative working area, has a total of 28 genera and 37 species of plants and over 70% genera are endemic. Several regional floras other than Yunnan have been discovered from southern China, as Pingyipu of Jiangyou, Yangling of Chongyi, and Shiqiao of Cangwu. Recently, a systematic palaeontological study based on materials from the Lower Devonian of Hezhang, Guizhou Province is conducted by the Devonian Investigation Group (DIG) of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Science (NIGPAS) , led by Prof. XU Honghe, and Dr. WANG Yao from Qufu Normal University. The related research results were published in international journals Review of Palaeobotany and Palynology and Philosophical Transactions of the Royal Society B. Abundant and diverse palynomorphs are firstly recovered from the megaplant fossil-bearing beds. The palynological assemblage is summarized as Retusotriletes triangulatus–Latosporites ovalis–Apiculiretusispora plicata (TOP) and contributes a better understanding of the Lower Devonian palynoflora of South China. Hezhang TOP palynological assemblage is dominated by trilete spores and includes 36 genera and 72 species of spores. Qualisaspora sinuata and Gneudnaspora divellomedia var. divellomedia, are for the first time discovered from the Lower Devonian of China. The TOP assemblage also dates the Danlin Formation as Pragian to early Emsian (Early Devonian) and indicates a coastal palaeoenvironment with co-occurrences of acritarch and scolecodont. The new finds of megaplant fossils from the Lower Devonian of Hezhang County, Guizhou Province, include Zosterophyllopsida Demersatheca and Euphyllophytopsida Pauthecophyton. Demersatheca contigua consists of cylindrical strobili with four longitudinal rows of sporangia decussately arranged and shows great similarities to the plant from Yunnan and Guangxi localities. Pauthecophyton hezhangensis has distinct fertile units with grouped sporangia and each unit with two or three fusiform sporangia. A new phytogeographical zone of Hezhang, Guizhou is recognized, which shows similarities with other coeval floras and contributes to a further understanding of Early Devonian flora of South China. The whole South China Plate is subdivided into four sub-regions, eastern Yunnan, Guizhou, Cathaysia, and Sichuan based on their different floral compositions. The Guizhou sub-region shares some taxa with the eastern Yunnan and Cathaysia sub-regions within South China. The common plant members of these regions are distributed around the epicontinental sea. It is suggested that the Guizhou sub-region might act as a bridge aiding plant dispersal from eastern Yunnan to Cathaysia during the Early Devonian. References: Wang Y, Bai J, Liu B-C, Wang Y, Xu H-H. 2022 New insights into the South China Lower Devonian flora based on fossils from Hezhang, Guizhou Province. Philosophical Transactions of the Royal Society B377, 20210312. https://doi.org/10.1098/rstb.2021.0312. Xu HH, Yang N, Bai J, Wang Y, Liu F, Ouyang S. 2022 Palynological assemblage of the Lower Devonian of Hezhang, Guizhou, southwestern China. Review of Palaeobotany and Palynology 297, 104561. https://doi.org/10.1016/ j.revpalbo.2021.104561. Fig1. Megaplant fossils and spores from the Lower Devonian Danlin Formation, Hezhang, Guizhou Province
Fig 2 Lower Devonian flora regions on the South China palaeogeographical map. The red dashed line with arrows and numbers indicate the probable plant dispersal routes and sequence
A new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. This is the currently earliest record of angiosperms in the North America, and its geographical position indicates that angiosperms were already widespread in the North Hemisphere during the Jurassic. This new information prompts a rethinking on the history of angiosperms and related hypotheses. A new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. This is the currently earliest record of angiosperms in the North America, and its geographical position indicates that angiosperms were already widespread in the North Hemisphere during the Jurassic. This new information prompts a rethinking on the history of angiosperms and related hypotheses. Recently, Prof. WANG Xin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), published this result in the international academic journal Biosis: Biological Systems. This is also the first time that Chinese scientists have independently studied early angiosperm fruit fossils, which from North America. The fossil was collected from an outcrop of the Simon Formation near Tezoatlán, nine miles south of the city Tezoatlan, Oaxaca, Mexico. The fossils are preserved as coalified compressions embedded in yellowish siltstones (Fig. 1a). By using stereomicroscope equipped with a digital camera, the researcher observed and photographed the fruits are round-shaped, with an apical and a basal depressions, 10-13.6 mm long, 10-13 mm wide, including a seed and an enclosing pericarp (Figs. 1a-b,). The pericarp has a smooth surface, the seeds are inside the fruits, round in shape, approximately 8 mm long and 6-9 mm wide (Fig. 1a-b). A persistent style 76 μm long and 30 μm wide is in the apical depression (Fig. 1b-c). Epidermal cells of the exocarp are polygonal or rectangular in shape, 20-60 μm long, 13-38 μm wide (Figs. 2d-e). Anomocytic stoma is surrounded by approximately five epidermal cells, 36 μm long, 36 μm wide, with a slit 25 μm long, 5.4 μm wide, level with neighboring epidermal cells (Figs. 2d-e). If Dilcherifructus were taken as a seed, less hard seed content enclosed by a hard seed coat should not be visible for an observer. The situation in Dilcherifructus (Figs. 1b) is on the contrary: the inside content is obvious. This observation suggests that the internal body in Dilcherifructus is harder than the enclosing layer, a case frequently seen in angiosperm fruits: seeds inside ovary usually are harder than the enclosing fleshy ovarian wall and thus visible when squashed. The distal projection in Dilcherifructus is interpreted as a persistent style on the tip of a fruit, as frequently seen in angiosperms. Its Jurassic age suggests that origin of angiosperms is much earlier than widely accepted, while its occurrence in the North America indicates that angiosperms were already widespread in the Jurassic, although they were still far away from their ecological radiation, which started in the Early Cretaceous. This research was supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Wang Xin, The currently earliest angiosperm fruit from the Jurassic of North America, Biosys: Biological Systems, 2021, 2(4): 416-422, doi:10.37819/biosis.001.04.0160. https://eaapublishing.org/journals/index.php/biosis/article/view/160/229.
Fig. 1. General morphology of Dilcherifructus mexicana gen. et sp. nov and its details
Fig. 2. Stomata of fossil fruits under microscope
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
