A research team led by NIGPAS reported the oldest, morphologically specialized, and obligate termitophiles from mid-Cretaceous Burmese amber, which represent the oldest known termitophiles, and reveal that ancient termite societies were quickly invaded by beetles about 99 million years ago. The result has been published in Current Biology on April 13th, 2017.
The oldest termitophile from 99-million-year-old Burmese amber, Cretotrichopsenius burmiticus (Image by Cai et al., 2017) Eusocial insects, such as ants, social wasps and bees, and termites, include some of the most ecologically ubiquitous of terrestrial animals. The nests of these insects are well protected and provide a safe, communal space for the storing of resources and production of brood, so the nests are often cohabited by various highly specialized symbionts that take advantage of the abundant resources and protection inside the nests. Termitophiles, symbionts that live in termite nests, include a wide range of morphologically and behaviorally specialized organisms. Understanding of the early evolution of termitophily is challenging due to a scarcity of fossil termitophiles, with all known reliable records occurring from the Miocene Dominican and Mexican ambers (approximately 19 million years ago). Mesozoic termitophiles are of great significance for understanding the origin of eusocial societies of termites and the early evolution of specialized termitophily. Recently, a research team led by Dr. CAI Chenyang and Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences reported the oldest, morphologically specialized, and obligate termitophiles from mid-Cretaceous Burmese amber (approximately 99 million years ago), which represent the oldest known termitophiles. The result has been published in Current Biology on April 13th, 2017. To integrate into the hosts’ societies, termitophilous beetles have repeatedly evolved physogastry (swollen abdomens) and limuloid (horseshoe-crab-shaped) body shapes, representing the two principal forms. Both morphological adaptations have arisen convergently many times in beetles (Coleoptera) as well as in flies (Diptera). The peculiar fossil rove beetles, named as Cretotrichopsenius burmiticus Cai et al., 2017, exhibits the characteristic features of the modern aleocharine tribe Trichopseniini, including the articulation of the hind leg whereby the coxae are fully fused and incorporated into the metaventrite.
Ecological reconstruction of the mid-Cretaceous termitophille (Image by Cai et al., 2017) Cretotrichopsenius burmiticus has a protective horseshoe-crab-shaped body form typical of many modern termitophiles, with concealed head and antennae and strong posteriorly directed abdominal setae. The discovery represents the earliest definitive termitophiles, pushing back the fossil record of termitophiles by 80 million years. Recent species of Trichopseniini are usually associated with derived neoisopteran termites of Rhinotermitidae, and less frequently with Termitidae. Interestingly, some trichopseniines are known to live within nests of the basal-most termites (Mastotermitidae) and drywood termites (Kalotermitidae). Because host specificity is rather low in extant trichopseniines, it is certainly likely that Cretotrichopsenius may have been associated with the variety of termite groups known from Burmese amber. The fossils reveal that ancient termite societies were quickly invaded by beetles about 99 million years ago. This study was jointly supported by the Chinese Academy of Sciences, the National Natural Science Foundation, the Natural Sciences Foundation of Jiangsu Province, and the Ministry of Science and Technology of China. Reference: Chenyang Cai, Diying Huang, A. F. Newton, K. T. Eldredge, M. S. Engel, 2017. Early evolution of specialized termitophily in Cretaceous rove beetles. Current Biology doi: 10.1016/j.cub.2017.03.009
Courtship behaviours, frequent among modern insects, have left extremely rare fossil traces. Recently, Scientists described three male damselflies showing ancient courtship behaviour from mid-Cretaceous Burmese amber. The new findings provide suggestive evidence of damselfly courtship behaviour as far back as the mid-Cretaceous. Embargo: 10am UK time, the 20th of March 2017 photograph and line drawing of specimen Yijenplatycnemis huangi (Image by ZHENG Daran) Courtship behaviours, frequent among modern insects, have left extremely rare fossil traces. In odonates, the male must persuade the female to mate in tandem and the female should be willing to engage her genitalia with the male’s. Many territorial odonatans display their courtship by high-frequency wing-beats towards an approaching female. Most courtship, mating and parenting (social-sexual) behaviour cannot be preserved and fossil reports are few and ambiguous. No courtship behavious were previously recorded for fossil odonatans. Recently, Dr. ZHENG Daran and Prof. WANG Bo from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences described three male damselflies showing ancient courtship behaviour from mid-Cretaceous Burmese amber. These fossils were named Yijenplatycnemis huangi after Mr. Huang Yijen from Taiwan, for his generously donation of the type specimen. Y. huangi has spectacular extremely expanded, pod-like tibiae, helping to fend off other suitors as well as attract mating females, increasing the chances of successful mating. The new findings provide suggestive evidence of damselfly courtship behaviour as far back as the dinosaur age. Modern Platycnemidinae and Chlorocyphidae convergently acquired similar but less developed structures. During courtship, male Platycypha caligata waves the white anterior surface of all six laterally enlarged tibiae at the females, but uses the posterior surface of the tibiae for intra-sexual signaling during territorial defense. Similarly, male East Asian Platycnemis species with expanded, feather-like tibiae well differentiated from the females, exhibit a strong sexual dimorphism. The males display their white legs in a fluttering flight in front of females before mating. By morphological inference, the six extremely expanded tibiae of Y. huangi could also have a signaling function for courtship displays. Platycypha has all six tibiae expanded, but all less so than Y. huangi in size. Platycnemis has more expanded mid and hind tibiae, but is still smaller than Y. huangi. These more expanded fossil tibiae suggest an extreme adaptation for courtship behaviour. More importantly, unlike Platycypha and Platycnemis, the tibiae of Y. huangi are asymmetric and pod-shaped, especially the hindleg tibia with a semi-circular outline. This pod-like shape would make waving slower due to air resistance. Y. huangi waving its giant pod-like tibiae would make males more easily noticed and attract female attention, increasing mating opportunities and implying sexual selection. Reconstruction showing the courtship behavior (Image by YANG Dinghua) The tibial shape of Y. huangi also resembles the wings of some members of the extinct neuropteran families. The tibiae of Y. huangi are hyaline and partly covered with two narrow brown bands, making them even more like pigmented wings. In addition, there is an eye-shaped spot in the middle of the hindleg, quite like the wing spots in Kalligrammatidae and some recent butterfly eyespots. These well-developed eyespots were and are used to make a conspicuous and contrasting display to intimidate vertebrate predators or protect the body by deflecting an attack to the wings. Deflective eyespots in butterflies and fossil lacewings are smaller than deimatic ones and both are never on the legs, but dragonflies are predators with good eyesight, and the tiny ones in Y. huangi may have less to do with paralleling fossil lacewings in deflecting nearby predators and more to do with raising the interest of females (cf. peacock eyespots). That none of the pigmented tibiae in Y. huangi are damaged, however, suggests they did not precipitate an aggressive response. This research was recently published in Scientific Reports, and supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences, and the HKU Seed Funding Program for Basic Research. Reference: Daran Zheng, André Nel, Edmund A. Jarzembowski, Su-Chin Chang, Haichun Zhang, Fangyuan Xia, Haoying Liu, Bo Wang, 2017. Extreme adaptations for probable visual courtship behaviour in a Cretaceous dancing damselfly, Scientific Reports, 7:44932; doi: 10.1038/srep44932. WANG Bo bowang@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Related News: https://www.eurekalert.org/pub_releases/2017-03/caos-cbt031717.php http://www.dailymail.co.uk/sciencetech/article-4330808/Damselflies-trapped-100-million-year-old-amber.html http://www.ibtimes.co.uk/extremely-rare-amber-fossils-capture-100-million-year-long-flirt-1612578 https://phys.org/news/2017-03-courtship-behavior-million-year-old-amber.html http://gizmodo.com/this-poor-cretaceous-damselfly-has-been-waiting-100-mil-1793438939 http://www.telegraph.co.uk/science/2017/03/20/coitus-interruptus-frisky-insect-trapped-100-million-year-old/ https://www.aol.com/article/news/2017/03/20/100-million-year-old-courtship-behavior-preserved-in-amber/21903624/
Recently, a research team led by Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology reported a diversity of gilled mushrooms and mycophagous rove beetles from Burmese amber, the latter belonging to Oxyporinae, modern members of which exhibit an obligate association with soft-textured mushrooms. Their finding displays an ancient ecological community assembling diverse mushrooms and beetles and established on specialized trophic interaction by this early date. The results have been published in Nature Communications on 16th March, 2017. Mushrooms, or Agaricomycetes, are common, conspicuous and morphologically diverse fungi. Most agaricomycete fruiting bodies are ephemeral, so they are extremely rare in fossils. Up to now, all described species of gilled mushrooms, or Agaricales, have been known exclusively from amber. Among them, two forms are from the Mesozoic, including the earliest mushrooms, Palaeoagaracites antiquus from 99-million-year-old Burmese amber, and the slightly younger Archaeomarasmius leggetti from New Jersey amber (about 90 million year old). The remaining three species are known from early Miocene Dominican amber, some 20-million-year-old. Evidence indicating the origin and early diversification of Agaricomycetes is very limited. Recently, a research team led by Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) reported a diversity of gilled mushrooms and mycophagous rove beetles from Burmese amber, the latter belonging to Oxyporinae, modern members of which exhibit an obligate association with soft-textured mushrooms. The results have been published in Nature Communications on 16th March, 2017. All the mushrooms they studied are very well-preserved and can be grouped in four forms. A stalk and a complete intact cap containing distinct gills are visible in most of these amber mushrooms. The new discovery suggests a long-term evolutionary stasis of body form for at least 99 million years and highlights the palaeodiversity of mushrooms, pushing back the presence of agarics by at least 25 million years. More interestingly, the mouthparts of these early oxyporine rove beetles, including enlarged mandibles and greatly enlarged apical labial palpomeres with dense specialized sensory organs, match those of modern taxa and indicate a mushroom feeding habit of these beetles. The diverse and morphologically specialized oxyporine beetles had also been appeared by the Early Cretaceous, some 125 million years ago. Their finding displays an ancient ecological community assembling diverse mushrooms and beetles and established on specialized trophic interaction by this early date. This study was jointly supported by the Chinese Academy of Sciences, the National Natural Science Foundation, the Natural Sciences Foundation of Jiangsu Province, and the Ministry of Science and Technology of China. Reference: Chenyang Cai, R. A. B. Leschen, D. S. Hibbett, Fangyuan Xia, Huang Diying, 2017: Mycophagous rove beetles highlight diverse mushrooms in the Cretaceous. Nature Communications doi: 10.1038/ncomms14894
Diverse mushrooms in 99-million-year-old Burmese amber (Image by Cai et al.)
Diverse mycophagous oxyporine rove beetles (Image by Cai et al.)
Details of mouthparts of extinct and extant mycophagous oxyporine rove beetles (Image by Cai et al.)
Ecological reconstructions of Cretaceous mushrooms and mycophagous beetles (Image by Cai et al.) HUANG Diying dyhuang@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences
Recently, a research team has found a new morphologically specialized beetle, Cascomastigus monstrabilis, from the mid-Cretaceous Burmese amber, shedding new light on the predator–prey associations in the late Mesozoic terrestrial ecosystem. Recently, a research team led by researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) has found a new morphologically specialized beetle from the mid-Cretaceous Burmese amber, shedding new light on the predator–prey associations in the late Mesozoic terrestrial ecosystem. Insects exhibit various morphological specializations specific to particular behaviors, and these permit the reconstruction of palaeobiological traits. Dr. CAI Chenyang at NIGPAS and Dr. YIN Ziwei at the Shanghai Normal University discovered three exceptionally well-preserved fossils of highly specialized ant-like stone beetles (Staphylinidae, Scydmaeninae) from mid-Cretaceous Burmese amber, some 99 million years ago. These fossils, named as Cascomastigus monstrabilis Yin & Cai, 2017, are represented by both male and female, and belong to a small tribe called Mastigini. These early beetles display morphological modifications on the antennae unknown among living ant-like stone beetles and associated with predation on springtails (Collembola), a widespread and abundant group of significantly greater geological age. Cascomastigus has an extremely large body size, elongate clubbed maxillary palpi, toothed mandibles, and more importantly, slender and highly modified antennae that functioned as an antennal setal trap. Such an antennal modification is analogous to that of the modern ground beetle genus Loricera (Carabidae, Loricerinae), a group possessing a specialized antennal setal trap exclusively for the capture of springtails. Springtails, usually only a few millimeters long, are one of the most widespread and abundant of terrestrial arthropods, and is the most diverse group of Entognatha, the sister group to insects. The earliest known springtails, Rhyniella praecursor, are from the Early Devonian Rhynie chert (Scotland, approximately 400 million years ago), and Mesozoic and Cenozoic ambers have witnessed the explosive radiation of this usually overlooked group. Burmese amber also harbors abundant and diverse springtails, which sometimes occur in groups. Therefore, the springtails are potential ideal food resource for these litter-dwelling beetles. The tribe Mastigini display a disjunctive distribution, occurring in South Africa and southern Europe. The new discovery of Cascomastigus from northern Myanmar further highlights the once broader distribution of Mastigini. All previously known specialist predators of springtails are confined to the middle Eocene. Cascomastigus from about 99 million years ago represents the earliest known predators specialized for capturing springtails, pushing back the age of such predation by at least 54 million years. This study is jointly supported by the Chinese Academy of Sciences, the National Natural Science Foundation, the Natural Sciences Foundation of Jiangsu Province, and the Ministry of Science and Technology of China. Reference: Zi-Wei Yin, Chen-Yang Cai*, Di-Ying Huang & Li-Zhen Li, 2017. Specialized adaptations for springtail predation in Mesozoic beetles. Scientific Reports, DOI: 10.1038/s41598-017-00187-8 (*corresponding author) CAI Chenyang cycai@ nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Cascomastigus monstrabilis, Image by YIN Ziwei
A severe mass extinction event happened during the Devonian-Carboniferous transition (about 359 Ma heretofore), which causes the extinction of >45% genera and ~21% of marine invertebrate families. Typical sedimentary rocks from the Rhenish Massif, western German, are global distributed (Hangenberg black shale, Hangenberg shale and Hangenberg sandstone in ascending order), resulted from the prominent marine anoxia and global sea-level changes. Hence, this end-Devonian mass extinction event is also named as Hangenberg mass extinction event. Recent comprehensive analyses show that the Hangenberg event lasted from the latest Devonian to the earliest Carboniferous (e.g., ~100-300 kyr; uppermost Lower Siphonodella praesulcata Zone to lowest Siphonodella sulcate Zone). Microbial carbonates usually flourished after the mass extinction events, taking the end-Permian mass extinction event for example. Proliferation of microbial carbonates was generally attributed to the reduced competition from multicellular organisms after mass extinctions, resulted in lower levels of grazing and/or bioturbation of microbial communities. In addition to metazoan competition, flourishing microbial carbonates were also supported by a high seawater calcite saturation state (SCSS), which must have enhanced microbial calcification and carbonate production. The decline of marine metazoans and the SCSS in that time is much higher than those in the Early Triassic during the Hangenberg extinction transition. Therefore, microbial carbonates should have thrived in the early Tournaisian. However, the documented bioconstructions dominated by stromatolites and/or thrombolites to date are rare, and can only be founded in Australia. Skeletal and microbial reef ecosystems are two opposite elements of the marine biosphere, which could be used to unravel the marine ecosystem evolution during the mass extinctions. In order to unravel the changes in the marine biosphere across the Hangenberg extinction transition, Dr. YAO Le, Prof. WANG Xiangdong, and Dr. CHEN Jitao from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Prof. ARETZ Markus from the University of Toulouse Ⅲ, and Prof. WEBB Gregory E. from the University of Queensland, recently studied the stromatolites from Northwest China in great detail. Their materials came from the Qianheishan Formation at the Dashuigou section in Ciyao area, Pingchuan County, Gansu Province, China, containing volume of rock 200 m in width and 16 m in thickness. The age of the stromatolites is constrained to the earliest Carboniferous, which is equal to the conodont zone of Lower Siphonodella sulcate, based on the comprehensive analysis of ammonoid, ostracod and palynological biostratigraphy. In addition, the bryozoan and brachiopod fossils, the fine-scale laminations and the fenestral structures in the Qianheishan stromatolites suggest that they formed in the normal marine environment. Hence, the stromatolites described in this study are the production of marine microbial proliferation after the Hangenberg event. The Qianheishan stromatolites are mainly composed of micrite, peloids, small oncoids, and sparry calcite, which are formed by the microbial baffling, binding and calcification. Three stromatolite morphology types are distinguished, including laminar, wavy-laminar and domal forms. With other early Tournaisian microbe-dominated bioconstructions extensively distributed on shelves, the Qianheishan stromatolites support an event of microbial carbonate proliferation after the Hangenberg extinction. In order to confirm this hypothesis, a lot of quantified study of the microbe-dominated has been taken systematically. The result embraced the hypothesis that the marine biosphere has been significantlymodified, changing from the stromatoporoid-coral reef ecosystem to microbial ecosystem. In the early Tournaisian, the microbe-dominated bioconstructions were globally distributed in western America, eastern Russia, eastern Australia, northern India and northwestern and southern China (between 40° latitude on both sides of the palaeoequator) and that their abundance increased more than ten-fold in the early Tournaisian compared to the latest Devonian (Strunian). This result indicates that the microbial carbonate proliferation occurred after the Hangenberg mass extinction event. The proliferation of the microbial carbonates following the Hangenberg extinction event is related to the declined metazoan diversity and the increased calcification rates. However, it remains unclear that which of the two controlling factors is dominant. Reconstruction of the relative abundance of skeleton- and microbe-dominated bioconstructions is a new insight to solve this problem. For this purpose, the changes in the relative abundance of skeleton- and microbe-dominated bioconstructions during the Hangenberg and “Big Five” mass extinction transitions, respectively, are constructed. Comparing them to the reality, we found that the increase of the abundance of microbe-dominated bioconstructions is consistent with the decline of skeleton-dominated bioconstruction abundance after mass extinctions, implying that the abundance of skeletal bioconstructors plays a crucial role in regulating the proliferation of microbial carbonates in the aftermath of mass extinctions. This paper was published in Scientific Reports and financially supported by the National Natural Science Foundation of China, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences and the Ministry of Science and Technology Foundation Project and the Centre national de la recherche scientifique (CNRS) Project. Reference: Yao, L., Aretz, M., Chen, J.T., Webb, G.E., Wang, X.D., 2016. Global microbial carbonate proliferation after the end-Devonian mass extinction: Mainly controlled by demise of skeletal bioconstructors. Scientific Reports 6, 39694; doi: 10.1038/srep39694.
Field (a, b and c), polished-slab (d) and thin-section (e and f) photographs of the Qianheishan stromatolites at the Dashuigou section, Gansu Province, northwestern China.
Comparison of the variations in the relative abundance between skeleton- and microbe-dominated bioconstructions across the Hangenberg and ‘Big Five’ mass extinction transitions.
Stromatoporoid-coral reef ecosystems have collapsed and disappeared during the Frasnian-Famennian and Hangenberg mass extinction events during the late Devonian and Devonian-Carboniferous transition, respectively. In addition, prominent glacial and interglacial events accompanied by frequent sea-level fluctuations occurred during the Carboniferous. They all have an important influence on the evolution of the Carboniferous reefs. The Devonian and Permian are periods of global reef expansion, while the Carboniferous is a period of global low reef abundance, with a few reef cases documented. To date, it is still unclear about the composition and evolutionary process of the Carboniferous reefs. Reefs are complex ecosystems and their growth and demise are closely related to changes in the abundance of potential reef-builders, temperature, relative sea level, and palaeogeography. During the Carboniferous, the South China Block was located near the equator, with warm climate and extensively successive carbonate sequence which provide suitable conditions for the development of reefs, and then for the studies on the reef composition and evolution and their relationships to the palaeoenvironmental changes during this time interval. The published and new data on reefs, main reef-builders (corals, bryozoans, calcareous algae etc.), and palaeoenvironmental proxies (glacial records, sea-level changes etc.) during the Carboniferous were systematically reviewed by Dr. YAO Le and Prof. WANG Xiangdong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences. The types, abundance, and distribution of Carboniferous reefs in South China were relatively simple, low and limited, respectively. The reef types mainly include metazoan reef (coral reef/biostrome and bryozoan-coral reef), algal reef (red algal and phylloid algal reefs), microbial reef (stromatolite and Tubiphytes reefs) and carbonate mud mound (Waulsortian carbonate mud bank), which were distributed mainly at the platform or isolated platform margins and slopes in Qian-Gui areas. In South China, the Carboniferous reefs underwent the evolutionary episodes of the recovery, decline and turnover, which were controlled mainly by reef-builders abundance, sedimentary facies, and relative sea-level changes. Metazoan flourishing, carbonate facies development with relative sea-level rise are in favour of developing metazoan reefs, such as during the Viséan and late Bashkirian-middle Kasimovian times. On the contrary, metazoan decline, non-carbonate facies formation due to relative sea-level fall leads to metazoan reef decrease, as in the Tournaisian and Serpukhovian times. From the Mississippian to Pennsylvanian, the changes from metazoan reefs into algal reefs are caused primarily by the development of shallow-water carbonate facies that resulted from relative sea-level fall. Although some differences can be recognized in the different time scales, the reef evolution in South China is consistent with that of globe during the Carboniferous. Besides, the transgressive and regressive events in South China correspond to the growing and retreating of Gondwana glaciation. They all suggest that global climate cooling and warming may also influence the reef evolution in South China during this time. This paper was published in Palaeoworld and financially supported by the National Natural Science Foundation of China and the Ministry of Science and Technology Foundation Project. Reference: Yao, L., Wang, X.D., 2016. Distribution and evolution of Carboniferous reefs in South China. Palaeoworld, 25: 362-376.
Main reef types of the Carboniferous reefs in South China (A) Carbonate mud mound (Waulsortian carbonate mud bank); (B) Coral reef; (C) Microbial reef (Stromatolite reef mound); (D) Algal reef (Phylloid algae reef) Overview of lithostratigraphical column with indications of reef intervals, shelf geometry, and climate A: Carbonate mud mound; B: Metazoan reef; B1: Coral reef; B2: Bryozoan-coral reef; B3: Coral biostrome; C1: Red algae reef; C2: Phylloid algae reef; D1: Stromatolite mound; D2: Tubiphytes reef
Fossil wood is among the significant proxies for terrestrial paleoclimate and paleogeographical reconstruction in Earth history. Abundant and diversified Mesozoic fossil woods are well recorded in China; however, Triassic fossil wood is rare. A Sino-French research team leading by Prof. WANG Yongdong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(NIGPAS) have found a new fossil wood from the Late Triassic Xujiahe Formation (Norian to Rhaetian) in Guangyuan of northern Sichuan Basin, southwestern China (dated to ca. 200 Ma). The fossil wood material consists of two well-preserved specimens yielding secondary xylem with distinct growth rings. Bordered pits on the radial tracheid walls are mostly contiguous, biseriate alternate, locally uniseriate and strongly flattened. Cross-fields show a large window-like pore. This anatomy is typical for an important fossil wood morphogenus Xenoxylon Gothan. Based on a novel combination of radial and cross-field pitting type and ray height, a new species, Xenoxylon guangyuanense sp. nov. is recognized. The finding of this new fossil wood taxon contributes to a better understanding of the yet poorly documented Xenoxylon early radiation during the Late Triassic. This study was conducted by Dr.TIAN Ning (Shenyang Normal University), Prof. WANG Yongdong and Dr. LI Liqin from NIGPAS, Dr. Marc Philippe from University of Lyon 1, France, as well as other experts from Qufu Normal University and Chinese Academy of Geological Sciences, Beijing. Xenoxylon is a paleobiogeographically significant conifer genus, which is considered to be an index for the cooler and/or wetter climates of Northern Hemisphere throughout theLate Triassic–Late Cretaceous range. The occurrence of Xenoxylon in the Sichuan Basin of southern China may indicate a short-term cooling event episode, sandwiched within a period during which warm and wet climate conditions largely prevailed over lower latitude regions of the Northern Hemisphere. Such a cooling event in the Sichuan Basin which was located at a low paleolatitude on the eastern rim of Tethys may be in accordance in time with the temperature decline event in Norian–Rhaetian boundary uncovered by oxygen isotope (δ18O) record in Italy of the western rim of Tethys. This study is jointly supported by the State Key Programme of Basic Research of Ministry of Science and Technology, China, National Natural Sciences Foundation of China, Innovation Project of CAS and the funding from State Key Laboratory of Palaeobiology and Stratigraphy (NIGPAS). Related information: Tian N, Wang Y D*, Philippe M, Li LQ, Xie XP , Jiang ZK , 2016. New record of fossil wood Xenoxylon from the Late Triassic in the Sichuan Basin, southern China and its palaeoclimatic implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 464: 65-75(*corresponding author).
Anatomical structures of Xenoxylon guangyuanense sp. nov. from the Upper Triassic of the Sichuan Basin, showing growth rings, trachrids and cross-field pitting
A joint team of researchers from China and Britain has revealed a new fossil fauna, the Anji Biota, which document post-extinction sponge-dominated communities from uppermost Ordovician rocks of South China. More than 75 sponge species represent multiple lineages that survived the Late Ordovician mass extinction. Sponges also flourished after other mass extinctions and may have facilitated ecosystem recovery by stabilizing sediment.
Diverse 444 million-year-old sponges from the Anji Biota of China, thriving as everything around them died (by Botting, J. P.) New deposits with exceptionally well-preserved fossil communities are always exciting, but some are more interesting than others. Windows into particularly important times or environments can tell palaeontologists much more than narrow views into a time that is already well known. A window into the aftermath of the second-biggest mass extinction since the rise of animals is therefore very interesting indeed. The end-Ordovician crisis, 445 million years ago, resulted in 85% of species dying out. It was the result of a sudden, intense ice age, followed by an equally rapid warming, and corresponding changes in ocean chemistry and circulation. The plankton started to recover quite quickly, but until now we have known little about life on the deeper parts of the sea floor. The only exceptional fossil deposit known from this interval before now is the peculiar glacial lagoon environment of South Africa's Soom Shale. A joint team of researchers from China (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, et al.) and Britain (National Museum Wales) has revealed a new fossil fauna preserving delicate skeletons and soft tissues, from the immediate aftermath of the Ordovician mass extinction. The Anji Biota was discovered in the bamboo forests of Zhejiang Province, China, in a narrow band of mudstone exposed at several sites up to 10 km apart. The fauna is extraordinarily diverse, with nearly 100 species found in the first phase of collecting. The surprise, though, is that this diversity is almost entirely composed of sponges. The Anji Biota records an astonishing range of different sponge species, in many different major groups, with a total diversity exceeding that of equivalent modern faunas. Most post-extinction survivor ecosystems are made up of small, stunted species that managed to thrive and are found everywhere. In the Anji sponge fauna, the sponges are large and complex, and although some species formed forests on the sea floor, many others were very scarce or extremely localised. It doesn't look like a survival fauna at all; these simple animals were flourishing. Sponges were not quite the only animals on the sea floor, however. Together with thousands of sponges, a few conical-shalled nautiloids were also recovered, and a single fossil sea scorpion complete with legs. The sea scorpions were a very rare group in the Ordovician, and well-preserved specimens are almost entirely limited to these sites of exceptional preservation. Why was this post-extinction world so completely dominated by sponges? As lead author Joe Botting explains, “We think the sponges thrived because they can tolerate changes in temperature and low oxygen levels, while their food source (organic particles in the water) would have been increased enormously by the death and destruction all around them.” Sponges are known today as ecosystem engineers, encouraging biodiversity by stabilising sediment and providing habitats. In the case of the end-Ordovician crisis, such an abundance of sponges over wide areas might well have helped the ecosystem to recover. The team also notes that mass sponge remains have been recorded after other mass extinction events, suggesting that this is a common pattern after ecological collapse. There are lessons for the present, as well. If the past is anything to go by, then as marine ecosystems begin to collapse due to human activities, we should expect to see sponges rule the seas once again. Reference: Botting, J. P., Muir, L. A., Zhang Y-D.*, Ma, X., Ma, J-Y., Wang, L-W., Zhang, J-F., Song, Y-Y., Fan, X., 2017. Flourishing sponge-based ecosystems after the End-Ordovician mass extinction. Current Biology. http://dx.doi.org/10. 1016/j.cub.2016.12.061.
Radiodontans - Giant predators in Paleozoic seas Recorded in exceptionally preserved Lagerst？tten, the radiodontans (including anomalocaridids) are cosmopolitan, soft-bodied, stem-group arthropods that inhabited Paleozoic seas. They are notable for their unique morphology, peculiar ecology and basal position in arthropod evolution. The early Cambrian Chengjiang Lagerst？tte has yielded some of the oldest radiodontans, including three unquestionable taxa – Anomalocaris saron, Amplectobelua symbrachiata and Lyrarapax unguispinus. However, recent discoveries of the Burgess Shale Hurdia Walcott, 1912 and the Fezouata Aegirocassis benmoulae Van Roy et al., 2015 highlight the presence of another radiodontan group (Hurdiidae) characterized by a tripartite head sclerite complex consisting of one central element and a pair of lateral elements. Recently, Dr. ZHAO Fangchen and PhD. candidate ZENG Han from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and their colleagues reported six morphotypes of possible hurdiid head sclerite elements from the Chengjiang Lagerst？tte, some of which are closely associated with other typical radiodontan body parts. These sclerite elements provide detailed anatomy, such as mammillary tubercles and soft tissue reticulate structure, to help understand the morphology and biology of all hurdiid head sclerites. A common single dorsal plate in Anomalocaris saron and Amplectobelua symbrachiata is confirmed. Although the morphologically diverse central and lateral elements of the Hurdiidae and the conserved dorsal plate of the Anomalocarididae and Amplectobeluidae reflect a major distinction in radiodontan body plans, they share a fundamental structure of double layers of cuticle. The Chengjiang specimens not only clarify the morphology and biology of the radiodontan head sclerites in general, but also illuminate the diversity and disparity of radiodontans in their early evolutionary history. This research was funded by the National Natural Science Foundation of China, the Ministry of Science and Technology of China, and the Chinese Academy of Sciences. Article information: Han Zeng, Fangchen Zhao*, Zongjun Yin, Maoyan Zhu. 2017. Morphology of diverse radiodontan head sclerites from the early Cambrian Chengjiang Lagerst？tte, south-west China. Journal of Systematic Palaeontology, doi: 10.1080/14772019.2016.1263685
Stratigraphic column and the sample depth in the Kuhfeng Formation at the Pingdingshan East Section in Chaohu City, Anhui Province. The Guadalupian Epoch represents one of the most critical intervals during the Earth history which is characterized by a series of global geological and biological events. Establishing the Guadalupian geological timescale is essential for evaluating the tempo of global geological events occurred in the Guadalupian. However, the Guadalupian is poorly constrained by radioisotopic dates in comparison with the high-precision dates from the Lopingian and lowest Triassic in South China and the Cisuralian in southern Urals, Russia. Recently, Dr. ZHANG Hua from Nanjing Insititute of Geology and Palaeontolgy, Chinese Academy of Sciences and his colleagues reported combined CA-ID-TIMS and SIMS U-Pb zircon geochronology for three ash beds from the base and lower part of the Kuhfeng Formation in the Chaohu area, southeastern China. The basal Kuhfeng Formation volcanic ash yields a CA-ID-TIMS weighted mean 206Pb/238U date of 272.95 ± 0.11 Ma (MSWD = 1.9, n = 7). That serves as the best estimate for the age of CGB in South China for the first time. This new date is 0.65 ± 0.51 myr older than the interpolated Cisuralian-Guadalupian boundary age from 2016 International Chronostratigraphic Chart (ICC) or the 2012 Geologic Time Scale, and is an improvement to the previous stage boundary calibrations. The new geochronology increases the duration of the Guadalupian Epoch to 13.85 ± 0.51 myr, 1.35 ± 0.57 myr longer than that of the ICC 2016. This work is supported by NSFC (41420104003, 41290260 and 41273081) and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB18030400). Wu, Q., Ramezani, J., Zhang, H.* (Corresponding author), Wang, T.T., Yuan, D.X., Mu, L., Zhang, Y.C., Li, X.H., Shen, S.Z., Calibrating the Guadalupian Series (Middle Permian) of South China, Palaeogeography, Palaeoclimatology, Palaeoecology. http://dx.doi.org/10.1016/j.palaeo.2016.11.011.
