A research group led by Prof. HUANG Diying from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences has systematically studied fossil water striders from the mid-Cretaceous of northern Myanmar (about 100 million years ago) in recent years. Now they have presented the first fossil record of a group of water striders in copulation. Fossilized mating insects are an irreplaceable tool for understanding the evolution of mating behaviors and life history traits in the deep-time record of insects. A research group led by Prof. HUANG Diying from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences has systematically studied fossil water striders from the mid-Cretaceous of northern Myanmar (about 100 million years ago) in recent years. Now they have presented the first fossil record of a group of water striders in copulation. The findings were published in Proceedings of the Royal Society B on April 3. According to the researchers, instances of copulation are particularly rare in fossil insects, especially aquatic species, thus limiting our understanding of relevant behavioral strategies across geological time periods. Based on a comprehensive analysis of the functional morphology and behavioral ecology of the fossilized water striders, the researchers revealed the mating behavior and potential sexual conflicts of Cretaceous water striders. Gerromorpha includes water striders and their relatives that are conspicuously adapted to motion, feeding, and mating on the water surface. They occupy a wide range of niches including freshwater, coastal, and even pelagic environments. The specialized morphology and diverse behavior of gerromorphans have become hot research topics in evolutionary biology, ecology, and even interdisciplinary studies, and have provided a theoretical basis for the development of biomimetic technology on water surfaces. The common gerromorphan mating system is characterized by strong sexual conflict, manifested as copulatory struggles between the sexes, along with a range of male behaviors such as harassment, coercive violation, and intimidation, while females resist costly mating attempts. The fossil record of gerromorphan insects is limited. For example, only one Mesozoic example of Gerridae has been found in French amber. In the specimen reported in this study, seven adults of Burmogerris rarus gen. et sp. nov., comprising three paired individuals and a single adult male, as well as four recognizable water strider nymphs are enclosed in an amber piece. Of these, two pairs were captured in mating situations, with smaller males riding on the backs of the females. In addition, two pairs and a single male appear to have been preserved in the same layer near the upper surface of the amber. “We speculate that the small-sized male B. rarus is unlikely to be territorial, while this species maintains a high population density in the Myanmar amber forest,” said Dr. FU Yanzhe from the research group. Morphological studies using confocal laser microscopy and fluorescence microscopy revealed sexual dimorphism in the protibiae of the new fossils: specifically, protibiae are slightly curved in males while they are straight in females. In addition, male protibiae have 15–17 discontinuous clusters of pegs along the innermost edge, forming a comb-like structure that is absent in females. “By comparing the male’s protibial combs with species in the related family Veliidae, we suggest that the specialized protibial comb of the new fossils functions as a grasping apparatus, likely representing an adaptation to overcome female resistance during struggles,” said Prof. HUANG. These paired fossils probably represent a stage of precopulatory struggle or postcopulatory contact guarding. Males used such contact guarding to prolong mating and thus avoid sperm competition. Since guarding could lead to prolonged association between males and females, the probability of being trapped by resin during mating increased. The researchers suggested that B. rarus males were more likely to actively search for females rather than adopt a sit-and-wait strategy. The new discovery in Myanmar amber has significant implications for understanding the early evolution of mating behavior in water striders. Drawing from insights into the paleoecology of the Myanmar amber biota and an analysis of the morphology, including body size, wings, legs, and claws, of the new fossils, this study suggests that B. rarus most likely inhabited small, slow-flowing water bodies, such as tidal pools, near the coast in the Burmese amber forest窗体顶端. The paired water striders Burmogerris rarus, from Myanmar amber
Photomicrographs of Burmogerris rarus
Ecological reconstruction
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Cestoda, commonly known as tapeworms, is a large class of the platyhelminth phylum with about 5000 species described to date. Recently, LUO Cihang, a PhD candidate, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), collaborated with other scientists from Yunnan University, and Germany, UK, , Myanmar, reported an enigmatic fossil from mid-Cretaceous Kachin amber (about 100 million years ago), on Geology on March 22, 2024. Cestoda, commonly known as tapeworms, is a large class of the platyhelminth phylum with about 5000 species described to date. Recently, LUO Cihang, a PhD candidate, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), collaborated with other scientists from Yunnan University, and Germany, UK, , Myanmar, reported an enigmatic fossil from mid-Cretaceous Kachin amber (about 100 million years ago), on Geology on March 22, 2024. This study thus probably provides not only the first partial body fossil of a tapeworm, but also arguably the most convincing body fossil of a flatworm, providing new evidence for the early evolution of tapeworm. Cestoda infect all major groups of vertebrate animals including humans and livestock, and can be found in almost all marine, freshwater, and terrestrial ecosystems. Their size is variable, ranging from less than 1 millimetre to more than 30 meters in length. Tapeworms are usually characterized by adults with a scolex (grasping head), a short neck, and a segmented body formed of multiple sets of genital organs (proglottids). Their scolex typically has hooks, suckers, or hooked tentacles, which can help them clung to the alimentary tract of their hosts. Most tapeworms have an obligatory parasitic life cycle involving two or three hosts. They have no mouth and digestive tract, and absorb nutrients directly from the gut of their hosts. The Order Trypanorhyncha is the most speciose tapeworm group in the marine realm, and it comprises one of the most ubiquitous and readily recognized parasites of marine fish. Trypanorhynch tapeworms are characterized by a scolex bearing 2 or 4 bothria, and a unique tentacular apparatus with four evaginable tentacles adorned with hooks as extensions of tentacle sheaths inside the scolex. Their larvae infect a wide variety of marine invertebrates (like crustaceans), as well as teleosts, and their adults are found in the stomach and intestine of sharks and rays. Molecular clock analyses calibrated by means of host fossil data estimate that trypanorhynch tapeworms had probably originated around the Triassic/Jurassic boundary (about 200 million years old), but their own fossils have never been found. In summary, the fossil records of tapeworms are extremely sparse due to their soft tissue and endoparasitic habitats, which greatly hampers our understanding of their early evolution. This fossil displays unique external (armature pattern) and internal (partially invaginated tentacle and rootless hooks) features which are most consistent with the tentacles of extant trypanorhynch tapeworms that parasitize marine elasmobranchs (mainly sharks and rays). Remarkably, nearly all extant trypanorhynchs are endoparasites of marine elasmobranchs, thus our study provides an exceptional example of a marine endoparasite trapped in amber, and sheds new lights on the taphonomy of amber. WANG says, “we reported the first body fossil of a tapeworm.” Tapeworms are thought to originate from the mid-Paleozoic based on their molecular framework, but their fossil record is extremely scarce due to their endoparasitic lifestyle. Although supposed tapeworm eggs were reported from a Carboniferous shark coprolite, the only widely accepted fossil record before the Quaternary is restricted to eggs discovered in a shark coprolite from the Permian, suggesting that the relationship between tapeworms and elasmobranch vertebrates was established at least by then. Although a tapeworm embryo was reported inside an egg, but it is putative due to the lack of confirmed characters. The new fossil is most consistent with the tentacle anatomy of a trypanorhynch tapeworm including the hook morphology, and thus represents the first body fossil of a tapeworm from the geological past. The new fossil presented the most convincing body fossil of a platyhelminth. Body fossils of the platyhelminth phylum are rare, with only a few examples. The oldest putative record comes from the Devonian of Latvia: circlets of hooks with sucker discs were found on placoderm and acanthodian fish. Although the arrangement of hooks is consistent with extant monogeneans, no other body structure was found. Two cysts that resemble trematode metacercariae were reported from mid-Cretaceous Kachin amber, however, no valid morphological details were given to support this. Lastly, the body fossil of Rhabdocoela discovered in Eocene Baltic amber has been plausibly reinterpreted as air bubbles. Therefore, this find represents the most convincing body fossil of a platyhelminth that has yet been found. The research indicated amber can preserve the internal structure of helminths. Using high resolution micro-CT, this study discovered that inside the fossil is a folded longitudinal structure appearing to run in a spiral around the longitudinal axis and it extends to the anteriormost part. This is in accordance with the invaginated tentacle of a trypanorhynch. Meanwhile, the rootless hooks are also the same as those of trypanorhynchs. Previous research has indicated that the internal structure can be preserved intact as in extant forms, but these studies are all focused on arthropods. “Our results highlight that amber can preserve the internal structure of helminths like tapeworms on geologic time scales”, says WANG. The research results provided a remarkable example of a marine endoparasite trapped in amber. Some gleicheniacean trichomes and one scale insect nymph are preserved together with the partial worm fossil in the same amber specimen, clearly indicating a terrestrial or onshore environment at the time of entrapment in resin. Moreover, there are many sand grains uniformly distributed inside the amber, implying that entrapment of the fossil occurred in a sandy environment. Furthermore, previous evidence shows that Kachin amber was deposited in a near-shore environment. Therefore, a possible scenario can be proposed: the elasmobranch host of the tapeworm was stranded by a tide or storm, for example. The trypanorhynch had an extruded tentacle in the dying host, and its host was bitten by a higher-level terrestrial predator or scavenger; when the host was ingested by the predator, the tentacle was pulled apart from the trunk, dislodged from the intestine and came stuck to some nearby resin. “Our study further supports the hypothesis that Kachin amber was probably deposited in a paralic paleoenvironment, and also highlights the importance of amber research in paleoparasitology”, add WANG. This research was supported by the National Natural Science Foundation of China, the Second Tibetan Plateau Scientific Expedition and Research, and the Deep-time Digital Earth (DDE) Big Science Program. Reference: Luo Cihang, Palm H.W., Zhuang Yuhui, Jarzembowski E.A., Nyunt T.T., Wang Bo, 2024. Exceptional preservation of a marine tapeworm tentacle in Cretaceous amber. Geology. https://doi.org/10.1130/G52071.1. The fossil tapeworm from mid-Cretaceous Kachin amber (~99 Ma; million years ago) and the comparison with the tentacle of an extant trypanorhynch tapeworm. (A) Microscopic image of fossil tapeworm. (B) Micro-CT image of fossil tapeworm. (C) Scanning electron microscopy image of an extant trypanorhynch tapeworm. The comparison of the internal structure of the fossil (A) with the tentacle of an extant trypanorhynch tapeworm (B). Abbreviation: ivt—invaginated tentacle. A hypothetical ecological reconstruction of the fossil trypanorhynch tapeworm (drawn by YANG Dinghua.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, Dr. JIANG Hui supervised by Professors WANG Bo and ZHANG Haichun from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led a collaborative cicada study with scholars from several countries. Their research aimed to clarify the early evolutionary history of Cicadoidea fossils, the phylogenetic relationships between Mesozoic fossils and extant Cicadoidea, the macroevolution of body structure adaptations, and their relationship with environmental changes. The related findings were recently published in Nature Communications. Recently, Dr. JIANG Hui supervised by Professors WANG Bo and ZHANG Haichun from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led a collaborative cicada study with scholars from several countries. Their research aimed to clarify the early evolutionary history of Cicadoidea fossils, the phylogenetic relationships between Mesozoic fossils and extant Cicadoidea, the macroevolution of body structure adaptations, and their relationship with environmental changes. The related findings were recently published in Nature Communications. Cicada, here referring to the superfamily Cicadoidea, is well-known for its evolution of sound production system, exceptional long-term subterranean habits, and symbolic attributes and utility in research that widely exists in culture, life, and science. Extant Cicadoidea includes the globally widespread Cicadidae, commonly known as true/singing cicadas, and relictual Tettigarctidae, found only in Australia and colloquially known as hairy cicadas. Currently, the earliest fossil of Cicadoidea was found in the Triassic. All Mesozoic (approximately 252 to 66 million years ago) Cicadoidea fossils have traditionally been classified into Cicadidae and Tettigarctidae based on a few distinct and conservative morphological features. However, this direct assignment of Mesozoic fossils to modern taxa may overlook the role of unique and transitional features provided by fossils in tracking their early evolutionary paths. This study explores the phylogenetic relationships of fossil and extant Cicadoidea groups for the first time. It reveals that Mesozoic Cicadoidea fossils include stem cicadoids, stem tettigarctids, and stem cicadids. Some Mesozoic fossils previously classified as Tettigarctidae might actually be closer to modern Cicadidae phylogenetically. The clades of Cicadidae and Tettigarctidae might have diverged at or by the Middle Jurassic. Due to preservation issues, the classification of insect fossils often relies on the preserved partial morphological features. This study conducted a morphological analysis of the partial structures of adults and nymphs, such as wings, non-wing body parts, and nymphal legs, to compare subtle continuous morphological changes with classification and phylogenetic outcomes. The research found that specialized homologous structures in insect fossils might contain previously overlooked identifiable transitional variations. An in-depth examination of these continuous morphological changes can provide a more precise understanding of the impact of spatiotemporal changes on morphological evolution and further clarify patterns of macroevolution. For example, changes in the head and labium might reflect resistance adaptations due to feeding pressures from host plant changes. Additionally, changes in the thoracic notum, and alterations in wing venation and outline, may indicate the evolution of flight muscles and capabilities. Changes in the head and thorax can also be quantified and compared. Producing sounds is a vital communication method for many animals. Modern Cicadidae species can produce the loudest sounds among insects, reaching nearly 120 decibels via tymbal mechanisms. In contrast, Tettigarctidae communicate with subtler vibrational signals transmitted through the substrate, lacking the ability to produce loud sounds. The varied sound-producing mechanisms between Cicadidae and Tettigarctidae ignite curiosity about the initial evolution of their acoustic structures and behaviours. In this study, tymbals were identified in all Mesozoic cicadoid stem groups, preserved in both male and female specimens. This is the first identification of tymbal structures in Cicadoidea fossils, capturing this communication method in the fossil record. The majority of relatively intact fossils lacked elements for intricate sound production and auditory systems, suggesting mid-Cretaceous cicadoids may have relied on substrate-transmitted vibrations for communication, rather than producing or perceiving high-decibel songs. Additionally, there are instances where the discovery of tymbal muscles and an abdominal cavity in a fossil, alongside preserved tracheae, flight muscles, and Marplesian tubes, suggests the possibility of an inherent abdominal cavity and resonating abilities similar to those found in the abdomens of modern singing cicadas. Consequently, the study posits another hypothesis: certain mid-Cretaceous Cicadoidea groups may have generated sounds louder than substrate-transmitted vibrations. Anyway, compared to modern singing cicadas, the species of Cicadoidea might have been relatively silent for the majority periods of Mesozoic. This study also reports the oldest known Cicadoidea nymph and exuviae fossils from mid-Cretaceous Kachin amber. The prominently powerful fossorial forelegs of these nymphal fossils, akin to modern cicadas, suggest similar behaviours and robust capabilities for digging, soil transportation, and subterranean living. Cicada nymph and adult fossils show distinct ecological niches and survival strategies, with a notable shift from underground root feeding to above-ground stem feeding. Evidence of root feeding is infrequently found in fossils. However, cicada nymph fossils with specialized digging forelegs suggest this behaviour. This subterranean lifestyle presumably conferred a survival benefit, enabling extended underground habitation for cicada nymphs. This study also examines the occurrence of root feeding among arthropods in the fossil record. Given the adult and nymph Cicadoidea fossils from Kachin amber and the multitude of adult fossils from the Middle Jurassic Daohugou deposit, it's evident that mid-Mesozoic Cicadoidea demonstrated distinct life stage niches, facilitated biomass transfer from underground to above-ground, and influenced ecosystems in a manner akin to their modern cicadas. This work is jointly funded by the National Natural Science Foundation of China and the Chinese Academy of Sciences. Reference: Jiang Hui, Szwedo J., Labandeira C.C., Chen Jun, Moulds M.S., Mahler B., Muscente A.D., Zhuo De, Nyunt T.T., Zhang Haichun, Wei Cong, Rust J., Wang Bo (2024) Mesozoic evolution of cicadas and their origins of vocalization and root feeding. Nature Communications, 15: 376. https://doi.org/10.1038/s41467-023-44446-x. Adults, final instar nymph, and exuviae of Cicadoidea fossils in Kachin amber of Myanmar. Digital reconstructions from micro-CT data reveal a diverse array of morphologies throughout the evolution of Cicadoidea. Specialized fossorial forelegs of fossil and extant cicada nymphs. Phylogenetic and morphological analyses-based relative relationships discrimination and reconstruction. Life reconstruction of cicadas in the Mesozoic forest.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Dany Azar, from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS) and the Lebanese University, has reported in Current Biology on December 4, 2023, which have found the earliest known fossil mosquito in Lower Cretaceous amber from Lebanon. What’s more, the well-preserved insects are two males of the same species with piercing mouthparts, suggesting they likely sucked blood. Dany Azar, from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS) and the Lebanese University, has reported in Current Biology on December 4, 2023, which have found the earliest known fossil mosquito in Lower Cretaceous amber from Lebanon. What’s more, the well-preserved insects are two males of the same species with piercing mouthparts, suggesting they likely sucked blood. “Lebanese amber is to date the oldest amber with intensive biological inclusions and it is a very important material as its formation is contemporaneous with the appearance and beginning of radiation of flowering plants, with all what follows of co-evolution between pollinators and flowering plants” said D. Azar. Among modern-day mosquitos, only females are hematophagous, meaning that they use piercing mouth parts to feed on the blood of people and other animals. “Molecular dating suggested that the family Culicidae arose during the Jurassic, but previously the oldest record was mid-Cretaceous,” said André Nel of the National Museum of Natural History of Paris (Muséum National d’Histoire Naturelle de Paris). “Here we have one from the early Cretaceous, about 30 million years before.” The Culicidae family of arthropods includes more than 3,000 species of mosquitoes. Female mosquitoes are notorious for their blood-feeding ways, which has made them a major vector for spreading infectious diseases. Hematophagy in insects is thought to have arisen as a shift from piercing-sucking mouthparts used to extract plant fluids. For example, blood-sucking fleas likely arose from nectar-feeding insects. But the evolution of blood-feeding has been hard to study in part due to gaps in the insect fossil record. In the new study, researchers describe two male mosquitos with piercing mouthparts, including an exceptionally sharp, triangular mandible and elongated structure with small, toothlike denticles. The new findings suggest that male mosquitoes in the past fed on blood as well, according to the researchers. They also help to narrow the “ghost-lineage gap” for mosquitoes, they say. They report that the mosquitos’ preservation in amber extends the definitive occurrence of the mosquito family of insects into the early Cretaceous. It also suggests the evolution of hematophagy was more complicated than had been suspected, with hematophagous males in the distant past. In future work, Nel says they want to learn more about the 'utility' of having hematophagy in Cretaceous male mosquitos. They’re also curious to explore “why this no longer exists,” he says. This work was supported by the National Natural Science Foundation of China.. Reference: Dany Azar, Andre Nel, Diying Huang, Michael S. Engel, The earliest fossil mosquito, Current Biology (2023), https://doi.org/10.1016/j.cub.2023.10.047. Dorsal view of male mosquito in amber. Detail of mouthparts using a confocal microscope; scale bar, 10 μm Age recovery of fossil mosquito in Lower Cretaceous amber from Lebanon
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
The movement reconstruction of extinct vertebrate animals has been extensively studied, such as the gait of dinosaurs and the movement patterns of other extinct quadrupeds. How about the invertebrate animals such as extinct ants? Recently, a team led by Prof. WANG Bo from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS) proposed a set of universal research methods for reconstructing the movement of invertebrate animals. Their findings were recently published in the journal National Science Review. The movement reconstruction of extinct vertebrate animals has been extensively studied, such as the gait of dinosaurs and the movement patterns of other extinct quadrupeds. How about the invertebrate animals such as extinct ants? Recently, a team led by Prof. WANG Bo from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS) proposed a set of universal research methods for reconstructing the movement of invertebrate animals. Their findings were recently published in the journal National Science Review. In comparison to vertebrate animals, research on the movement reconstruction of extinct invertebrate animals has been limited. This is primarily due to challenges related to the preservation of invertebrate exoskeletons (which are not as easily preserved), a lack of soft tissue data, and the complex nature of appendage structures. To address this research gap, Prof. WANG Bo collaborated with Prof. WU Jianing and Dr. BAO Tong from Sun Yat-sen University, chose to focus on the movement reconstruction of the extinct hell ants from the mid-Cretaceous period. Hell ants, which lived approximately 100 million years ago, represent some of the earliest known ants. They have no apparent close relatives among modern ants and are particularly known for their unique head structures, including prominent horn-like structures and sickle-shaped mandibles. The researchers selected one species of hell ant, known as the sickle mandible ant, for their study. The movement characteristics of the sickle mandible ant's mandibles had not been extensively studied. Based on previous anatomical data from hell ant fossils, it was hypothesized that Hell ants might have used their mandibles to capture prey by moving them vertically along the horizontal plane, in coordination with their horn-like structures. However, this hypothesis had uncertainties and was based on static information, necessitating validation through the acquisition of dynamic information. To address this issue, the researchers reconstructed the movement of the sickle mandible ant's mandibles in five steps. First, they selected two different amber fossils with distinct mandible spatial configurations. Second, they created three-dimensional models of the mandibles from the fossils, accurately reconstructing the mandibles' three-dimensional shapes and anatomical structures, resulting in two high-quality 3D models. Third, based on the 3D models, the researchers detected and digitized the hidden movement clues within the fossils by comparing the 3D models of the sickle mandible ant’s mandibles in different spatial positions, quantitatively analyzing the mandibles’ three-axis movement characteristics. Fourth, they validated the kinematic feasibility through biomechanical and robotic experiments, concluding that three-axis rotation was more suitable for improving the success rate of prey capture in hell ants. Fifth, they reconstructed the predatory scenarios of the hell ants through ecological restoration. This study proposed a comprehensive approach for animating invertebrate fossils through movement reconstruction. This method, demonstrated through robotics, provides insights into the kinematics of ancient ecosystems, catalyzing the integration of paleontology with other disciplines and opening doors for a multidimensional understanding of invertebrate paleobiology. The research was support from the National Natural Science Foundation of China and Chinese Academy of Sciences. Reference: Wang Zixin, Zhang Wei, Li Jiahao, Ji Wang, Yang Yunqiang, Bao Tong*, Wu Jianing*, Wang Bo*, 2023. Animating fossilized invertebrates by motion reconstruction. National Science Review, nwad268, https://doi.org/10.1093/nsr/nwad268. Figure 1. Two amber specimens of hell ants with different mandible state Figure 2. Three-dimensional models of different spatial forms Figure 3. The triaxial motion characteristics of the mandibles were obtained by quantitative analysis Figure 4. Robotic ant head featuring triaxial rotation and its predation performance Figure 5. The predatory scenarios of the hell ants through ecological restoration
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, the Early Land Plant working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, conducted a systematic paleoecological study based on plant fossils from the Lower Devonian of Guangxi. The related research results were published in an open-accessed journal of iScience. The study of paleoecology involves the fossil record and paleoenvironmental information of many kinds of organisms. Fossils preserved in strata usually have a certain relation with each other. It is an important means to understand the biological evolution and its environmental background to carry out multi-scaled comprehensive analysis and study on a variety of fossils preserved together. Recently, the Early Land Plant working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, conducted a systematic paleoecological study based on plant fossils from the Lower Devonian of Guangxi. The related research results were published in an open-accessed journal of iScience. Testate amoebae are a group of widespread microcosmic protists and play a crucial part in Earth’s biosphere. Testate amoebae stand out with their unique test (shell), usually 20–150 μm in size, and in the tree of eukaryotic life, are known as a polyphyletic group that consists of three unrelated taxonomic lineages. As free-living protists, extant testate amoebae are distributed in most kinds of freshwater or terrestrial habitats, e.g., river, pond, peat land and soil, but as well as in brackish and marine waters, and are of great significance to the flow of matter and energy in ecosystems. It has been generally considered that the evolutionary history of testate amoebae could be traced back to the late Tonian (early Neoproterozoic, ca. 800–720 Ma), as evidenced by the extensive records of marine vase-shaped microfossils in this period. However, not much is known about the Paleozoic testate amoeba fossils, as of now. The oldest unambiguous occurrence of Paleozoic testate amoebae is a freshwater arcellinid species from the Lower Devonian Rhynie chert followed by scattered reports from the upper Carboniferous and Permian. There is also rare knowledge about the internal structures of fossil testate amoebae. Except few possible reproductive cells or resting cysts in phosphatized or amber-preserved specimens. There were no any other bio-related structures inside the shells of fossil testate amoebae have been observed. In this study, a shallow-marine testate amoebae is firstly discovered as exquisitely preserved vase-shaped microfossils from the Lower Devonian Cangwu Formation in Guangxi, southwestern China, and based on morphological characters, interpret them as a new fossil species of arcellinid testate amoebae. Additionally, it is shown that distinct acetabuliform structures are preserved in the shell of these testate amoeba, and infers possible sources of these internal structures. “Our testate amoeba co-occurs with several types of plant remains, e.g. Zosterophyllum sinense and some rhyniophytoids, and more recently reported Houia (Euchelicerata)”,XU says, “it can be suggested that the fossil-bearing horizon represents a shallow-water marine environment.” These fossils extend the record of marine vase- shaped microfossils into the Early Devonian, during which the earliest freshwater testate amoebae occurred. Recent advances in molecular phylogeny and microbial paleobiology of testate amoebae raise a scenario that, within Arcellinida lineages, the marine-freshwater transition probably occurred multiple times and only during the Phanerozoic. That arcellinids occurred in both the freshwater and shallow-marine environments in the Early Devonian concurs with the very possibility. This work is a contribution to the Deep-time Digital Earth (DDE) Big Science Program. Reference: Wang K, Xu H-H*, Liu B-C, Bai J, Wang Y, Tang P, Lu J-F, Wang Y. 2023. Shallow-marine testate amoebae with internal structures from the Lower Devonian of China. iScience. 26(5), 106678. https://doi.org/10.1016/j.isci.2023.106678. Fig 1 Palaeoecosystem reconstruction of the Lower Devonian Cangwu Formation in southwestern China. Fig 2 Three-dimensional reconstruction of Cangwuella ampulliformis from the Lower Devonian Cangwu Formation, based on synchrotron radiation X-ray tomography.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Eurypterids (Arthropoda: Chelicerata), normally known as sea scorpions, are an important extinct group of Paleozoic chelicerate arthropods. Recently, researchers from China and England described a new Ordovician eurypterid, Archopterus anjiensis n. gen. n. sp., from the latest Ordovician (Hirnantian) Anji Biota of Zhejiang Province, South China. It represents the first unequivocal Ordovician and the oldest eurypterid recorded in China, adding new knowledge to early evolution of eurypterids in Gondwana. Eurypterids (Arthropoda: Chelicerata), normally known as sea scorpions, are an important extinct group of Paleozoic chelicerate arthropods. Recently, researchers from China and England described a new Ordovician eurypterid, Archopterus anjiensis n. gen. n. sp., from the latest Ordovician (Hirnantian) Anji Biota of Zhejiang Province, South China. It represents the first unequivocal Ordovician and the oldest eurypterid recorded in China, adding new knowledge to early evolution of eurypterids in Gondwana. The study was published in Journal of Paleontology in May. Eurypterids first appeared in the Ordovician, attained their maximum diversity during the late Silurian and early Devonian, and became extinct at the end of Permian. Bearing bizarre morphology and high ecological diversity, they occupied marine, freshwater, and even terrestrial environments, becoming an important medium for us to understand the transition of ecological environments in the Paleozoic, and have always attracted attentions of both researchers and the public. However, Ordovician eurypterids are extremely rare, to date, only 12 species of Ordovician eurypterids are known in the world, so any reported occurrence is of great significance to understanding their early evolutionary history. A joint working group of Prof. ZHANG Haichun, WANG Bo, ZHANG Yuandong, and PhD student WANG Han from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) reported a rare Ordovician eurypterid from the Wenchang Formation of Anji County, Zhejiang Province. “Archopterus anjiensis is characterized by a parabolic carapace, Hughmilleria-type prosomal appendages, vase-shaped metastoma, and three-segmented type A (female) genital appendage, estimated to have been 15 cm long.”, WANG Han says. Associated with diverse sponges, Archopterus anjiensis was found in a deep-water environment of several hundred meters deep. This occurrence, along with some Ordovician eurypterids from a normal marine environment, may indicate that some early eurypterids favored a relatively deeper-water environment than their post-Ordovician relatives. In addition, Archopterus anjiensis represents the oldest adelophthalmid and extends the stratigraphic range of this family to Late Ordovician (by about ten million years), making Adelophthalmidae the longest-living eurypterid family (Ordovician to Permian), and indicates that adelophthalmids have been found in the widest range of habitats of all eurypterid groups. This rare Ordovician sea scorpion from Zhejiang Province, along with continuous discoveries of eurypterid fossils in China indicates that there is a great potential for exploration in Paleozoic Gondwana areas. The emergence of new materials and progress of paleontological research methods will provide the basis for further comprehensive studies of Chinese eurypterids. This research was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China. Restoration artist YANG Dinghua (NIGPAS) made the life reconstruction. Reference: Wang, H., Braddy, S., Botting, J., & Zhang, Y. D. (2023). The first documentation of an Ordovician eurypterid (Chelicerata) from China. Journal of Paleontology, 1-6. https://doi.org/10.1017/jpa.2023.21. Fig.1 Fossils of Archopterus anjiensis. Fig.2 Life reconstruction of Archopterus anjiensis (Drawn by YANG Dinghua)
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
An unusually well-preserved “Marine Dwarf World” from 462 million years ago was found at Castle Bank, Wales by a team led by the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences. The site comprises over 150 species, with many of miniaturized body size. It is one of the world’s most unexpected fossil sites. An unusually well-preserved “Marine Dwarf World” from 462 million years ago was found at Castle Bank, Wales by a team led by the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences. The site comprises over 150 species, with many of miniaturized body size. It is one of the world’s most unexpected fossil sites. The study was published in Nature Ecology and Evolution on May 1. Castle Bank, in Powys, is one of the very rare sites where soft tissue and complete organisms are preserved, providing an unrivaled view of the evolution of life. Among the best of these sites are Burgess Shale-type faunas, named after the classic Burgess Shale fossil-bearing deposit in Canada. Many of these sites occur in rocks from the Cambrian period (542–485 million years ago), when recognizable animal fossils first appeared. However, almost none occur in post-Cambrian rocks. As a result, palaeontologists know a lot about Cambrian marine life, but less about how it evolved in the periods immediately afterwards. Castle Bank is from the middle of the succeeding Ordovician Period, some 462 million years ago, and rivals the best of the Cambrian deposits in diversity of fossils and extraordinary levels of preservation. The remarkable new assemblage was discovered in 2020 by Dr. Joe Botting and Dr. Lucy Muir, two authors of this study, near Llandrindod, central Wales. So far, well over 150 species have been recovered, almost all of them new. Many of the animals are very small, at only 1–3 mm long, but they preserve minute details. They range from arthropods like crustaceans and horseshoe crabs to various types of worms, sponges, starfish, and many, many more. In some animals, internal organs such as digestive systems and even nerves are preserved, together with the limbs of tiny arthropods and delicate filter-feeding tentacles. Such exquisite detail is known from the best Cambrian faunas, but not previously from the Ordovician. The Castle Bank fauna represents a community of diverse marine organisms from the Middle Ordovician, and many of the shelly fossils were normal for these rocks. In addition, the range of fossils also includes several unusual discoveries, from unexpectedly late examples of Cambrian animals looking like opabiniids (weird proto-arthropods with a long proboscis) and wiwaxiids (slug-like molluscs armored with scales), to tantalizing, unexpectedly early fossils that resemble modern goose barnacles, cephalocarid shrimps (which have no fossil record at all) and possibly even a marine relative of insects. The Cambrian witnessed the origin of the major animal groups. The Ordovician was a critical time in the history of life as well, with an extraordinary diversification of animals that produced hard skeletons and abundant fossils. In addition, more familiar ecosystems like today’s coral reefs appeared by the end of the Ordovician. Until now, however, a big “gap” has existed between these two evolutionary events. A new Burgess Shale-type fauna from the middle of this interval will help close this gap by answering questions about the animal shift from Cambrian fauna to Palaeozoic fauna and about the shift in ecosystems from the Cambrian style (which were similar across much of the world) to the much more diversified ecology we see today. A few papers describing sponges and one on a primitive relative of modern arthropods called Mieridduryn have been published based on this fauna. Many more papers will follow and collections are ongoing. According to Dr. Muir, “Most fossil deposits of this importance are studied for many decades, and this is likely to be no different!” Joseph Botting and two collaborators from NIGPAS, CAS (Y. D. Zhang, and J. Y. Ma) have been collaborating on the Konservat-Lagerstatte of Ordovician, and parts of this work, including the observation and analysis of some specimen and reconstruction, are completed in NIGPAS under the support of CAS. The Castle Bank fauna have important implication of the evolution of sponges, especially Hexactinellida, and is considered as transitional interwal between sponges of Cambrian and those of Anji fauna, another Burgess-Shale type fauna from Zhejiang, China they have been devoting themselves on for years. Fig. 1 Two animals having soft body in Castle Bank fauna. A, probable priapulid (NIGP175887); B, tubicolous problematic organism (NIGP175892). Fig. 2 Reconstruction of the Castle Bank community. (Image by YANG Dinghua)
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, Papers in Palaeontology represents the first study of morphological variation in Cribroconcha honggulelengensis using a geometric morphometric approach and demonstrating allometric growth patterns for this species. This study also makes comparisons with the ontogeny of extant ostracods and investigates the control factors of Ostracoda ontogeny. Recently, Papers in Palaeontology represents the first study of morphological variation in Cribroconcha honggulelengensis using a geometric morphometric approach and demonstrating allometric growth patterns for this species. This study also makes comparisons with the ontogeny of extant ostracods and investigates the control factors of Ostracoda ontogeny. Ostracoda is one of the most widespread and diverse groups of crustaceans occurring since the Early Ordovician with many thousands of described fossil species. However, despite being the most abundant ostracods during the Palaeozoic, the Subclass Podocopa remains poorly resolved (especially for the order Platycopida) in respect of its origin, evolution, ontogeny and phylogeny, due to the lack of soft-part and molecular evidences. Dr. SONG Junjun, Prof. HUANG Bing and Prof. QIE Wenkun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) made a thorough analysis of Cribroconcha honggulelengensis, which is a typical Platycopida species in the Late Devonian. In this study, a total of 178 specimens of C. honggulelengensis from the Upper Devonian Hongguleleng Formation of the Bulongour section in western Junggar, northwest of Xinjiang Uygur Autonomous Region (referred to as Xinjiang), NW China, were carefully selected. A combination of landmarks and semilandmarks were used to cover as many morphological details as possible for the geometric morphometric analysis. Five growth stages (i.e., Adult, from A-1 to A-4) of C. honggulelengensis have been recognized according to the result of Kernel density map combined with the length/height scatter plot. There is a strong relationship between shape and size, with juvenile specimens (from the stages A-4 to A-2), exhibiting higher variability in shape. During the early molt phase, the juveniles have rounded anterior and posterior borders with an ovate outline, while small and rare pores locate in the posteromedian of carapaces. As the valve grows larger, carapaces elongate with small radius of curvature at anterior and posterior borders, and the pores-transverse ridges area expands drastically, including large and dense pores. Compared with the living ostracods, the researchers made functional morphological analysis of C. honggulelengensis and deduced that as the ontological variable changes, its body plan may have changed in a direction that make it more favorable, namely, forage more efficiently and to flee from predators more quickly. The distinct ontogenetic shifts in C. honggulelengensis of the first allometric phase (i.e., stages A-4, A-3) and second allometric growth phase (i.e., Stage A-2) show that shape variation may be not only a result of genetic homogeneity, but also a response to environment adaptation for salinity, oxygenation and water energy. In this study, the researchers incorporate as much quantitative shape information as possible from the Late Devonian ostracods for the first time by applying the geometric morphometrics, and it will encourage the use of geometric morphometric analyses in ostracodology and other microfossils, especially for the Palaeozoic ostracods. This research was supported by the National Natural Science Foundation of China, and the Strategic Priority Research Program of the Chinese Academy of Sciences. Reference: Song, J. J. *, Huang, B., Qie, W.K., 2023. Allometry in Late Devonian Podocopa ostracods (Crustacea) and its implications for ostracod ontogeny. Papers in Palaeontology, e1480, https://doi.org/10.1002/spp2.1480.
Fig. 1. Kernel density maps with the Length/height scatter plot (A) showing the growth stages (B) of Cribroconcha honggulelengensis Song & Crasquin, 2017 (178 specimens) in the Upper Devonian Hongguleleng Formation of western Junggar, NW China.
Fig. 2. Plots for PC 1–2 (A) and PC 1–3 (B) of the Principal component analysis of the shape of right later view of Cribroconcha honggulelengensis Song & Crasquin, 2017 (178 specimens) in the Upper Devonian Hongguleleng Formation of western Junggar, NW China, visualizing shape variation by thin plate splines.
Fig.3. The linear regressions of the shape with length (A, B, C) and height of the stage A-4 (D).
Fig.4. Ecological reconstruction and life mode interpretation of Cribroconcha honggulelengensis Song & Crasquin, 2017 in the Upper Devonian Hongguleleng Formation of western Junggar, NW China
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Acoustic communication has played a key role in the evolution of animals especially vertebrates and insects, ranging from mating to warning calls and even including social learning. On December 13, 2022 PNAS published the novel insight from an international team of paleoentomologists on acoustic evolution of Mesozoic katydids and evolution of the Mesozoic soundscape. Acoustic communication is commonly used in behaviors such as courtship, mating, predation, and avoidance of natural predators. The result is an amazingly diverse and complex modern soundscape. The reconstruction of ancient acoustic signals is challenging, however, due to the extreme rarity of fossilized organs. Insects were the first terrestrial animals to use air-borne sound signals for long-distance communication. Among acoustically signaling insects, katydids stand out as an ideal source to investigate the evolution of acoustic organs and behavior. PhD student XU Chunpeng from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), under the supervision of Profs. WANG Bo and ZHANG Haichun from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), carried out a detailed and global investigation of fossil katydids from the Mesozoic Era (commonly referred to as the age of the dinosaurs). We research team reported the earliest tympanal ears and sound-producing system (stridulatory apparatus) in exceptionally preserved Mesozoic katydids. We also studied the stridulatory apparatus and wing morphology of Mesozoic katydids, calculating their probable singing frequencies and analyzed the evolution of their acoustic communication. “The newly found tympanal ears in prophalangopsids katydids from the Middle Jurassic Daohugou Konservat-Lagerst？tte represent the earliest-known insect ears, extending the age range of the modern-type auditory tympana by 100 million years to the Middle Jurassic, some 160 million years ago”, says XU Chunpeng. The reconstruction of singing frequencies of Mesozoic katydids and oldest tympanal ears demonstrate that katydids had evolved complex acoustic communication, including mating signals, inter-male communication, and directional hearing, at least by the Middle Jurassic. Also, katydids had evolved a high diversity of singing frequencies, including high-frequency musical calls, accompanied by acoustic niche partitioning—all at least by the Late Triassic (200 million years ago). WANG Bo says that “we suggest that acoustic communication could have been an important evolutionary driver already in the early radiation of terrestrial insects after the Permo-Triassic mass extinction.” The Early and Middle Jurassic katydid transition from extinct haglid- to extant prophalangopsid-dominated insect faunas coincided with the diversification of derived mammalian groups (clades) and improvement of hearing in early mammals, supporting the hypothesis of acoustic co-evolution of mammals and katydids. The high-frequency songs of Mesozoic katydids could even have driven the evolution of intricate hearing systems in early mammals, and conversely, mammals with progressive hearing ability could have exerted selective pressure on the evolution of katydids, including faunal turnover. Our findings demonstrate that insects, especially katydids, dominated the choruses during the Triassic, which is different from the modern soundscape. After the appearance of birds and frogs in the Jurassic, the forest soundscape became almost the same as the modern one in the Cretaceous, except lacking the sound of cicadas (which have less musical calls). And all of these results also highlight the ecological significance of insects in the Mesozoic soundscape, which has hitherto been largely unknown in the palaeontological record. This research was supported by the National Natural Science Foundation of China, Strategic Priority Research Program of the Chinese Academy of Sciences, and the Deep-time Digital Earth (DDE) Big Science Program. Reference: Xu Chunpeng, Wang Bo*, Wappler T., Chen Jun, Kopylov D., Fang Yan, Jarzembowski E.A., Zhang Haichun, Michael S.E. (2022) High acoustic diversity and behavioral complexity of katydids in the Mesozoic soundscape. PNAS, https://doi.org/10.1073/pnas.2210601119. Figure 1 Stridulatory files of Triassic katydids (A–C) and tympanal ears of Jurassic katydids (D–E). Figure 2 Frequency range of hearing in vertebrates (above) and frequency range of tones used by extant crickets and fossil katydids (below). Figure 3 The origins of some key acoustic evolutionary events according to the fossil evidence. Figure 4 Ecological restoration of singing katydids from the Middle Jurassic Daohugou Konservat-Lagerst？tte of China. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China A record of enhanced water cycle in the late Paleozoic icehouse
