Research Professor CHEN Zhe and PhD student LIU Yarong from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), has made progress in studying the Shibantan Biota in Yichang, Hubei Province, uncovering the oldest known complex three-dimensional burrow systems to date. Preserved in approximately 550-million-year-old strata, these trace fossils show that complex animal behaviors were modifying the seafloor environment nearly 10 million years earlier than previously thought.Research Professor CHEN Zhe and PhD student LIU Yarong from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), has made progress in studying the Shibantan Biota in Yichang, Hubei Province, uncovering the oldest known complex three-dimensional burrow systems to date. Preserved in approximately 550-million-year-old strata, these trace fossils show that complex animal behaviors were modifying the seafloor environment nearly 10 million years earlier than previously thought.The Ediacaran–Cambrian transition, around 539 million years ago, marks one of the most significant ecosystem revolutions in Earth’s history. A key driver of this ecological shift was the transition of metazoan behavior from simple two-dimensional surface activities to three-dimensional exploration deep into sediments. This “substrate revolution” transformed the seafloor from a uniform, matground-dominated system into a heterogeneously, bioturbated modern-style seabed, permanently altering the trajectory of Earth’s environmental and biological evolution.The researchers conducted a systematic study of trace fossils from the Shibantan Biota (approximately 550–543 million years old). They identified multiple ichnospecies within the genus Treptichnus and established a new ichnospecies, Treptichnus streptosus. By combining these findings with previously discovered three-dimensional trace fossils such as Lamonte and tadpole-shaped traces from the same biota, the study offers an in-depth analysis of the evolutionary and ecological significance of the emergence of animals’ vertical exploration behavior.The findings, published in Science Advances on Oct. 29, reveal that complex animal behaviors emerged on the eve of the Cambrian explosion.Treptichnus is a landmark trace fossil, representing the first “3D exploration” of sediments by animals, and holds importance in evolutionary biology, animal behavior, and ecology. The first appearance of T. pedum, a member of this genus, formally defines the Ediacaran–Cambrian boundary. The new discovery from the Shibantan Biota predates this revolutionary behavior. In addition to reporting the new species T. streptosus, the study identifies other ichnospecies including T. cf. bifurcus, T. rectangularis, and T. pollardi, demonstrating that animal burrowing behaviors had already achieved considerable diversity by this period.Furthermore, the Shibantan Biota preserves other three-dimensional burrows, such as Lamonte and tadpole-shaped traces. The concentrated occurrence of these vertical exploration behaviors reflects early sedimentary ecological stratification and complex foraging strategies, indicating a gradually enhanced ability of trace-making organisms to engineer substrates.The study found that Lamonte caused intensive bioturbation within the Shibantan Biota. This not only disrupted microbial mats on the sediment surface but also dismantled the ecological environment of Ediacara-type organisms that depended on these mats. This suggests bioturbation may have been a contributing factor to the first extinction event of the Ediacara biota around 550 million years ago.The emergence of these complex behaviors and their cumulative ecological effects intensified toward the end of the Ediacaran Period. This led to the gradual decline of microbial mats, continuously eroding the ecological foundation of Ediacara-type organisms while creating new ecological opportunities for the diversification of other metazoans. Driven by the synergy of various biological and non-biological factors, this process ultimately contributed to the profound ecosystem transformation during the Ediacaran–Cambrian transition.This research further confirms that the rich and diverse assemblage of trace fossils and body fossils preserved in the Shibantan Biota provides a window for studying major ecosystem changes at the transition between the Precambrian and Phanerozoic Eons.This work was supported by the National Natural Science Foundation of China.Reference: Zhe Chen* and Yarong Liu, Advent of three-dimensional sediment exploration reveals Ediacaran-Cambrian ecosystem transition, Sci. Adv. 11. https://doi.org/10.1126/sciadv.adx9449.Treptichnus in the Shibantan assemblage in the Wuhe area. Scale bars represent 2 cm.Schematic illustration of trace fossils in the Shibantan assemblage.
A research group led by Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reports three Jurassic orthopterans (grasshoppers and crickets, including katydids) (Prophalangopsidae: Aboilinae) from the Daohugou Biota (ca. 165 million years ago, Inner Mongolia, NE China) with forewing patterns strikingly similar to the bennettitalean (extinct seed-bearing, cycad-like group) leaves.A research group led by Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reports three Jurassic orthopterans (grasshoppers and crickets, including katydids) (Prophalangopsidae: Aboilinae) from the Daohugou Biota (ca. 165 million years ago, Inner Mongolia, NE China) with forewing patterns strikingly similar to the bennettitalean (extinct seed-bearing, cycad-like group) leaves.This represents the first unambiguous evidence in which both the mimicking insects and their plant models are preserved in the same bedding plane. The study was published online in Geology on August 28, 2025.Animals evolve diverse defensive strategies under predation pressure, and mimicry is one of the most effective in insects. Leaf mimicry occurs widely in Lepidoptera, Orthoptera, Neuroptera, Phasmatodea, and Mantodea, but fossil evidence has been scarce and often ambiguous.The studied fossils reveal two distinct mimicry types. In Aboilus stratosus, the forewings bear six to seven transverse rectangular bands and are bisected by a longitudinal stripe running from the base to the tip, resembling the distal portion of Anomozamites fronds (figure 3A). In Sigmaboilus sp., the forewing features an inclined, nearly longitudinal stripe running across the wing, connecting six transverse rectangular bands, resembling one lateral side of an Anomozamites frond, as if medially divided along the rachis to produce a symmetrical half frond (figure 3B). In the resting position, the paired forewings would form a complete frond with leaflets along a central rachis.Bennettitales were a major component of Mesozoic floras before the rise of the flowering plants. Leaves of Anomozamites were widely distributed across Laurasia from the Late Triassic to the Early Cretaceous and constituted a dominant element of the Daohugou flora. According to the statistics, both Aboilinae and Anomozamites exhibit a broadly similar trend in species richness, peaking in the Middle Jurassic and declining in the Early Cretaceous, suggesting potential ecological associations. Additionally, Aboilus and Sigmaboilus are representatives of large herbivorous insects in the Daohugou biota, and some Anomozamites leaves from the same beds exhibit shallow to deep scalloped incisions along the leaflet margins interpreted as evidence of herbivory damage. We infer that these Jurassic leaf-mimicking insects inhabited and fed on Anomozamites, and that this sustained ecological association may have provided a functional context for the evolution of leaf mimicry.The study further suggests that increasing predation pressure in the Jurassic may have driven the evolution of leaf mimicry. Although stem birds were rare during the Jurassic, the Daohugou biota hosted a diverse assemblage of potential predators capable of preying on prophalangopsids, including the gliding insectivorous Volaticotherium, the arboreal dinosaurs Epidendrosaurus and Epidexipteryx, and the insectivorous anurognathid pterosaurs Jeholopterus. In the Cenozoic, katydids evolved more elaborate mimicry forms, including dead leaf analogues and mimics of partially eaten leaves. This increasing specialization likely reflects intensified predation pressure, associated with the emergence and rapid diversification of modern avian lineages after the Late Cretaceous and the subsequent radiation of passerine birds during the Paleogene–Neogene transition.Orthopterans are among the most common herbivorous insects. Fossil evidence shows that their mimicry strategies have responded to the evolutionary turnover of dominant plant groups, from spore-bearing plants and gymnosperms during the Paleozoic and Mesozoic to angiosperms during the Cenozoic (figure 5). This finding highlights the dynamic interplay between plant community succession, predation pressures, and insect defensive strategies, expanding our understanding of the ecological significance and evolution of leaf mimicry in orthopterans.This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Jiangsu Funding Program for Excellent Postdoctoral Talent, and the Volkswagen Foundation. The research team included collaborators from Nanjing Institute of Geology and Palaeontology (NIGPAS) and Ludwig-Maximilians-Universität München (LMU Munich), with artwork by Sun Jie.Reference: Fu Y, Dong C, Fabrikant D, Cai C, Haug C, Haug J, Huang D. 2025. Unique leaf mimicry in Jurassic insects. Geology. https://doi.org/10.1130/G53399.1.Fi.1 Leaf-mimicking orthopteran fossils of Prophalangopsidae from the Daohugou biotaFig.2 Fossil leaves of AnomozamitesFig.3 Reconstructions of two prophalangopsid species exhibiting distinct types of mimicry on Anomozamites leaves.Fig.4 Paleoart illustration showing the two species’ leaf mimicry among Anomozamites in the Daohugou biotaFig.5 The relationship between orthopteran leaf mimicry and the dominant plant groups throughout different geological periods
A research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences has identified a fossil acanthocephalan, Juracanthocephalus, from the 160-million-year-old Daohugou Biota in Inner Mongolia, China. This finding was published in Nature.A research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences has identified a fossil acanthocephalan, Juracanthocephalus, from the 160-million-year-old Daohugou Biota in Inner Mongolia, China. This finding was published in Nature.Acanthocephalans, commonly known as thorny-headed or spiny-headed worms, are a group of endoparasitic worms found in both marine and terrestrial ecosystems. These medically significant parasites infect a wide range of hosts, including humans, pigs, dogs, cats, and fish. Acanthocephalans are characterized by their worm-like body shape and a retractable proboscis armed with rows of recurved (i.e., backward-facing) hooks for anchoring to the digestive tracts of their hosts. Historically classified as a distinct animal phylum, their highly specialized body plan has led to ongoing debates regarding their phylogenetic position.Morphological studies have proposed various hypotheses linking acanthocephalans to Platyhelminthes (flatworms), Priapulida (penis worms), or Rotifera (wheel animals). However, molecular phylogenetic analyses strongly suggest that acanthocephalans are a highly specialized subgroup within Rotifera. Despite this, the morphological disparity between endoparasitic acanthocephalans and free-living rotifers remains striking.Furthermore, the fossil record of acanthocephalans is exceptionally sparse due to their soft bodies—which were less likely to fossilize than harder ones—and concealed habitats. Until now, the only known fossil evidence consisted of four putative acanthocephalan eggs discovered in the coprolites of a Late Cretaceous crocodyliform. Due to the lack of body fossils, the origin and early evolution of acanthocephalans thus remain poorly understood.Using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), the research team conducted a detailed anatomical analysis of Juracanthocephalus and updated the morphological matrix of worm-like animals to support a comprehensive phylogenetic analysis.The results indicate that Juracanthocephalus represents a transitional form between free-living, jawed rotifers and jawless, endoparasitic acanthocephalans, bridging an evolutionary gap. This finding provides the first direct fossil evidence to help resolve the long-standing mystery of acanthocephalan origins.Juracanthocephalus has a fusiform body divided into a proboscis, neck, and trunk. The proboscis is equipped with strongly sclerotized, slightly curved hooks, while the ventral surface of the trunk features 38 lines of transverse, setaceous combs—a trait comparable to modern acanthocephalans. A possible alimentary tract is preserved in the proboscis, though no clear gut is visible in the trunk. The terminal end of the fossil displays a structure resembling the bursa of male acanthocephalans.Notably, Juracanthocephalus has a jaw apparatus composed of clustered, tooth-like units arranged in converging paired rows, with the jaws increasing in size posteriorly. This structure closely resembles that found in Gnathifera, a group that includes Gnathostomulida, Micrognathozoa, and Syndermata (which encompasses Rotifera and Acanthocephala).To determine the phylogenetic position of Juracanthocephalus, the research team compiled an updated morphological matrix incorporating both extant and extinct worm-like animals. The analysis identifies Juracanthocephalus as a stem-group acanthocephalan, sister to all extant acanthocephalans. This finding aligns with molecular phylogenetic analyses, which place acanthocephalans within Rotifera (including Monogononta, Bdelloidea, and Seisonidea).However, the precise placement of acanthocephalans within Rotifera remains contentious, with six competing hypotheses arising from molecular and morphological studies. When Juracanthocephalus is excluded from the morphological matrix, the results support Seisonidea as the sister group to all other Rotifera, consistent with previous morphological analyses but conflicting with molecular data.Conversely, incorporating Juracanthocephalus into the matrix positions Seisonidea as the sister group to Juracanthocephalus and all extant acanthocephalans, reconciling morphological and molecular phylogenetic analyses.The discovery of Juracanthocephalus provides a crucial reference for understanding the evolutionary innovations and body plan of acanthocephalans. Its hooked proboscis and large body size suggest that it was an endoparasite during the Jurassic period. Furthermore, this fossil implies that acanthocephalans may have originated in terrestrial environments and diverged from Rotifera no later than the Middle Jurassic.This study underscores the importance of transitional fossils in elucidating radical morphological changes in animal body plans. While molecular phylogenetics has revolutionized our understanding of evolutionary relationships, Juracanthocephalus highlights the indispensable role of fossil evidence in reconstructing the history of life.The research was supported by the National Natural Science Foundation of China, the IUGS “Deep-time Digital Earth” Big Science Program, and the Jiangsu Innovation Support Plan for International Science and Technology Cooperation Programme.Figure 1: Juracanthocephalus (a, overall view; b, artistic reconstruction) and the comparison with extant Acanthocephala (c). Scale bars, 2.0 mm (a, b), 0.5 mm (c).Figure 2: The backscatter scanning electron (BSE) image (a), overlay image of several elements concentrations (b) and elemental maps of carbon from energy-dispersive X-ray spectroscopy (c) of Juracanthocephalus. Scale bar, 2.0 mm.Figure 3: Simplified cladogram of Gnathifera showing Juracanthocephalus in red color.Figure 4: Phylogenetic tree from 50% majority rule bootstrap consensus tree of parsimony analysis. When Juracanthocephalus is included in the matrix, the results recover Seisonidea as the sister group to Juracanthocephalus + all extant acanthocephalans (a); when Juracanthocephalus is excluded from the morphological matrix, the results support the Seisonidea as the sister group of all other Rotifera (b).
In August 2024, the International Union of Geological Sciences published the Second 100 IUGS Geological Heritage Sites in IGC 2024 Busan, Republic of Korea, and the "Permian vegetation of the Wuda Fossil Site" (Inner Mongolia) led by NIGPAS was successfully designated and included.<!--!doctype-->
The meeting of the 60th anniversary of the International Union of Geological Sciences (IUGS) was hold in Spain from October 25 to 28, 2022 and the First 100 International Geological Heritage Sites were announced. The Ordovician Rocks of Mount Everest (China and Nepal), the Permian-Triassic Great Extinction and GSSPs of Meishan (China) and the Cambrian Chengjiang Fossil Site and Lagerst？tte (China). These three sites were mainly studied by NIGPAS together with its collaborators for decades and were luckily selected in the First 100 list.https://iugs-geoheritage.org/geoheritage_sites.
Parental care refers to the protection, care and feeding of eggs or offspring by parents, is considered as a significant behavioural adaptation in life-history traits. It has evolved independently multiple times in animals, e.g. mammals, birds, dinosaurs and arthropods, especially various lineages of social insects. Parental care refers to the protection, care and feeding of eggs or offspring by parents, is considered as a significant behavioural adaptation in life-history traits. It has evolved independently multiple times in animals, e.g. mammals, birds, dinosaurs and arthropods, especially various lineages of social insects. Brood care is a form of uniparental care where parents carry eggs or juveniles after oviposition and provide protection, enhancing offspring fitness and survival. However, very few fossil insects directly document such an ephemeral behaviour. Among Mesozoic insects, the only two direct fossil cases of brooding ethology are from the Early Cretaceous Jehol biota and mid-Cretaceous Burmese amber. In recent years, a research group led by Prof. HUANG Diying of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) systematically studied the water boatman Karataviella popovi, a representative insect from the Middle–Late Jurassic Daohugou biota of northeastern China. Of the 157 examined K. popovi fossils, 30 adult females were preserved with a cluster of eggs anchored on their left mesotibia. Various analytical technologies and methods have been used in this study, and a comprehensive analysis of functional morphology revealed the unique egg carrying behaviour of the Jurassic water boatman. The discovery represents the earliest direct evidence of brood care among insects, indicating that relevant adaptations associated with maternal investment of insects can be traced back to at least the Middle Jurassic, pushing back by approximately 40 million years. The relevant results were published online in Proceedings of the Royal Society B on July 13th. The true water bug superfamily Corixoidea, commonly known as the water boatman, is a common aquatic Hemipteran insect, occurs in various freshwater ecosystems worldwide. Extant water boatmen commonly deposit eggs on various subaquatic substances such as leaves or stems of aquatic vegetation, stones, and even on snail shells, carapaces of terrapins, and the exoskeletons of crayfish. The Jurassic water boatman K. popovi from the Daohugou biota bears a relatively large body, with its body length ranging from 11–15 mm. The specialized protarsi of K. popovi, combined with the five patches of setae on the head forming a trawl-like feeding apparatus, reflecting the highly specialized predatory behavior. The anostracan and the water boatman K. popovi represent the precursors and dominators in the same layer of the Daohugou beds, and they show high consistency with their emergence, radiation, prosperity, decline and extinction. After analysis of more than 700 anostracan eggs, we hypothesize that the abundant seasonally produced anostracan eggs in the Daohugou biota probably are the food source of K. popovi. The egg clusters of K. popovi are compact, and arranged in approximately 5–6 staggered rows, attached to and throughout the left mesotibia of adult females by short egg stalks. As inferred from the arrangement of the eggs, each row seems to have 6–7 eggs. The diameters of egg (without stalk) range from 1.14 to 1.20 mm. This study hypothesize that due to the potential high predation risk caused by abundant salamanders in the Daohugou biota and seasonal food resources, K. popovi may have been exposed to fierce ecological pressure in the Daohugou biota. The brooding behaviour developed in K. popovi probably reflected adaptations to habitat or an evolutionary response to the ancient lake ecosystem changes. The brooding behaviour of K. popovi most likely provided effective protection for eggs, largely avoiding the risks of predation, desiccation and hypoxia, which had important effects for its evolution, development and reproductive success. However, this selfless behaviour of K. popovi incurred high ecological costs, which causes an increased risk of predation. To our knowledge, carrying a cluster of eggs on a leg is a unique strategy among insects, but is not unusual in aquatic arthropods, in which this carrying behaviour even can be traced back to the early Cambrian Chengjiang biota. The water boatman K. popovi could be viewed as a plesiomorphic relic. Our discovery highlights the existence of diverse brooding strategies in Mesozoic insects, which are helpful for understanding the evolution and adaptive significance of brood care in insects. This work was supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences, and the International Postdoctoral Exchange Fellowship Program. FANG Yan and LI Yan-da provided for technical support, and SUN Jie prepared the reconstructive illustration. Figure 1. The morphological characters of Karataviella popovi. Figure 2. Brooding in Karataviella popovi. Figure 3. The specialized filter-capture apparatus in Karataviella popovi. Figure 4. Ecological reconstruction of Karataviella popovi. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Triprojectacites is an extinct fossil pollen group characterized by three projections at the equator, which mainly thrived during the Late Cretaceous. The Northern Hemisphere palynofloras during the Late Cretaceous can be divided into a Normapolles province and an Aquilapollenites province, the latter of which is represented by the existence of Triprojectacites. Triprojectacites is an extinct fossil pollen group characterized by three projections at the equator, which mainly thrived during the Late Cretaceous. The Northern Hemisphere palynofloras during the Late Cretaceous can be divided into a Normapolles province and an Aquilapollenites province, the latter of which is represented by the existence of Triprojectacites. Northeast China constitutes an important part of the Aquilapollenites Provincein yielding abundant fossils of this special pollen group. This pollen group is of great significance in the study of stratigraphic division and correlation of the Upper Cretaceous, palaeoecology and palaeoclimate during that timefor its unique morphology, high diversity, short distribution, and rapid evolution. However, due to the complexity in morphology, it is hard to be correctly observed, described and measured, resultingin a mess of its systematic classification and identification, which then has seriously hindered its scientific applications. Recently, WU, Yixiao, a Ph.D. candidate in Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), with her supervisor, Prof. LI, Jianguo, and others, carried out a detailed research on the morphology, systematics, geological distribution, and evolution of Triprojectacites based on the material froma scientific drilling well, SK-1, in the Songliao Basin. A series of results has been approached and published in international journals Grana and Cretaceous Research. The SK-1 well in the Songliao Basin is ideal for the study of Triprojectacites for its highly detailed research, particularly the high-precision chronological framework. A total of 101 samples have been checked from the well to observe pollen morphology under optical, scanning electron, and transmission electron microscopes using single-grain technology. The morphological features of Triprojectacites have been clarified, including its shape, polarity, aperture, ornamentation and wall structure. A standardized morphological terminology and measuring method have been proposed. Finally, eight genera were screened out from the thirty-nine genera that have been proposed in relation with Triprojectacites. A classification system at generic level of Triprojectacitesis established. The composition and distribution of generaand species of Triprojectacites was investigated through the SK-1 well, exhibiting a five-phase evolution of Triprojectacites in the Songliao Basin as occurrence, radiation, steady development, climax, and extinction. During its evolution, Triprojectacites tend to be larger in size, more robust and complicated in ornamentation, and bearingaccessory structures. These research advances have laid a solid foundation for the research andapplication of Triprojectacites in species classification and evolution, and will promote its use in the study of global division and correlationof terrestrial Cretaceous strata, palaeoecology, and palaeogeography as well. These studies were jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China. Rereference: Wu, Y., Li, J., 2022. Genus classification of Triprojectacites Mtchedlishvili, 1961 emend. Stanley 1970. Grana, 61(3): 161–181. https://doi.org/10.1080/00173134.2022.2050804. Wu, Y., Li, J., Lin, M., & Koppelhus, E., 2022. Triprojectacites in the Songliao Basin, Northeast China: Systematics, biostratigraphy and evolution. Cretaceous Research, 135: 105193. https://doi.org/10.1016/j.cretres.2022.105193. Figure 1 SEM, TEM images of major ornamentationtypes in Triprojectacites Figure 2 Genera and species diversity of Triprojectacites in the Songliao Basin Figure 3 Evolution of each genera and species of Triprojectacites in the Songliao Basin
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
The reconstructed complex ecosystem based on the present Liexi fauna provides new evidence for the significant biotic turnover from Cambrian to the Palaeozoic evolutionary faunas, by showing a mixture of Cambrian relics, and the Ordovician new arrivals. In the 1980s, the famous palaeontologist Prof. Sepkoski proposed the diversity curve of the marine animal, recognized three evolutionary faunas, and proposed the concept of Ordovician radiation. From the beginning of the Ordovician, marine life started its great radiation, as manifested by the rapid appearance of new orders, families, and genera, together with the replacement of existing groups. The Great Ordovician Biodiversification Event (GOBE) constructed the essential framework of the Palaeozoic Evolutionary Fauna, while the Cambrian faunas dominated by the arthropods were replaced by the Palaeozoic faunas represented by the filter feeders and reef-forming organisms. GOBE was primitively studied and defined with the skeletonized taxa, rather than the non-mineralized taxa. The exceptionally preserved Lagerstatten have been assessed as reflecting the living community, providing new evidence to know the Ordovician marine world. However, only several Ordovician Lagerst？tten have been discovered before, especially in the Early Ordovician. Recently, a new Lagerstatte, Liexi fauna, was reported by the research team from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Hunan Museum and Central South University, from the Lower Ordovician of Yongshun country, Hunan Province. This work has been published online in Proceedings of the Royal Society B. The Liexi fauna has been discovered from the Madaoyu Formation of Lower Ordovician near the Liexi village, Yongshun county, Hunan Province. The conodont and graptolite assemblages indicate an age of mid-Florian, Early Ordovician, which is slightly younger than the Fezouata biota from Morocco and the Afon Gam biota from Welsh. Most of the documented fossiliferous Early Ordovician Lagerstatten globally are interpreted to occur in high latitude regions, such as the Fezouata biota near the South Pole, and the Afon Gam biota from North Wales at a palaeolatitude of 60°S. During the Early Ordovician, South China was thought to be a typical tropical palaeogeographical setting. In contrast to some other Ordovician Lagerstatten preserved in restricted or anoxic environments, the depositional environment of the Liexi fauna is interpreted to be offshore to the lower shoreface, following the palaeogeographic setting. The Liexi fauna includes up to 11 phyla of marine animals. The fauna is characterized by abundant, diverse biomineralized fossils along with the exceptional preservation of some non-mineralized tissues and groups. In addition to rich palaeoscolecidans and diverse trilobites (including the digestive tract preservation), the fauna also contains graptolites, extraordinarily complete echinoderms, exceptionally-preserved sponges, possible Ottoia, machaeridian polychaetes, and other rare biomineralized specimens, signalling a flourishing Early Ordovician marine fauna. A biologically complex and complete marine ecosystem with diverse organisms and varied lifestyles is proposed here, including endobenthic, sessile benthic, mobile benthic, nektonic, and planktic taxa. Any discoveries of Early Ordovician Lagerstatten are of significant concern for the research on the Cambrian to Ordovician faunal transition. The Liexi fauna is suggested as the age of middle Floian, probably preceding the GOBE’s primary interval of diversification by ~5–10 Myr. The reconstructed complex ecosystem based on the present Liexi fauna provides new evidence for the significant biotic turnover from Cambrian to the Palaeozoic evolutionary faunas, by showing a mixture of Cambrian relics, and the Ordovician new arrivals. This research is supported by CAS Strategic Priority Research Program (B) and National Nature Science Foundation of China. Reference: Fang, X., Mao, Y.Y., Liu, Q., Yuan, W.W., Chen, Z.Y., Wu, R.C., Li, L.X., Zhang, Y.C., Ma, J.Y., Wang, W.H., Zhan, R.B., Peng, S.C., Zhang, Y.D., Huang, D.Y.*, 2022. The Liexi fauna: a new Lagerstatte from the Lower Ordovician of South China. Proceedings of the Royal Society B, 289: 20221027. https://doi.org/10.1098/rspb.2022.1027.
Fossils from the Liexi fauna
Palaeoscolecidan worms from the Liexi fauna
Ecological reconstruction of the Liexi fauna (Drawn by J. Sun)
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
