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
Western Sichuan Basin . Scale bar = 20 μ m . Fig . 2 Carnian palynofloral composition revealing paleoclimatic setting in Jiangyou area Fig . 3 Correlation of the carbon-isotope records and palaeoclimate proxies between eastern and western Tethys during the mid-Carnian .H/X ratio : hygrophyte/xerophyte ratio . Contact : LIU Yun , PropagandistEmail : yunliu @ nigpas . ac . cnNanjing Institute of Geology and Palaeontology , Chinese Academy of SciencesNanjing , Jiangsu 210008 , China. The Late Triassic Carnian Stage witnessed major climatic changes during the mid-Carnian (Julian 2-Tuvalian 1), known as the “Carnian Pluvial Episode” (CPE). The CPE is characterized by increased rainfall, humid and warmer climate, oceanic anoxia, carbon cycle perturbations and demise of carbonate platforms. The global extent of the CPE-related humid climate and their impact on the terrestrial ecosystem are the major highlighted issues for the studies. Recently, Dr. LI Liqin, Prof. WANG Yongdong and their group from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), and Prof. Wolfram M. Kürschner from the University of Oslo, investigated the palynoflora from the Ma’antang Formation at Ma’antang section in Jiangyou area, western Sichuan Basin, and reconstructed Carnian paleovegetation and paleoclimatic setting in this area. The research results were recently published in Review of Palaeobotany and Palynology, an international journal. The Ma’antang section in the Jiangyou area is the type section the Ma’antang Formation. The previous ammonite and conodont studies have established a relatively reliable geological age frame work for this formation. Diverse and well-preserved sporomorphs were identified from the Ma'antang Formation at Ma'antang section, and two palynological assemblages were distinguished. The study reveals dominance of fern spores (represented by Dipteridaceae/Matoniaceae) in the Ma’antang palynoflora, especially in the middle part of the Ma’antang Formation. Lycopsid spores and gymnosperm pollen (including conifers, cycadophytes/ginkgophytes and seed ferns) are much less abundant. This palynofloral composition reflects a general humid climate setting in the western Sichuan Basin during the Carnian. Overwhelming predominance of wet Lowland SEG and hygrophyte elements, and increased Lowland/Hinterland as well as hygrophyte/xerophyte ratios observed in Units 2-4 of the Ma’antang Formation, suggesting intensified humidity during the Julian 2 in this area. This study correlates well with observations from North China as well as western Tethys, thus further supports a global nature of humid climate associated with the CPE. This study presents the first palynological evidence for vegetation changes and humid climate during the CPE in South China, providing important evidence for better understanding the terrestrial vegetation response to the CPE from the eastern Tethys area. This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, and the State Key Laboratory of Palaeobiology and Stratigraphy. Reference: Li, L.Q., Kürschner, K.M., Lu, N., Chen, H.Y., An, P.C., Wang, Y.D.*, 2022. Palynological record of the Carnian Pluvial Episode from the northwestern Sichuan Basin, SW China. Review of Palaeobotany and Palynology, 304: 104704. https://doi.org/10.1016/j.revpalbo.2022.104704.
Fig. 1 Representative fossil spores from the Ma’antang Formation at Jiangyou, western Sichuan Basin. Scale bar= 20 μm.
Fig. 2 Carnian palynofloral composition revealing paleoclimatic setting in Jiangyou area
Fig. 3 Correlation of the carbon-isotope records and palaeoclimate proxies between eastern and western Tethys during the mid-Carnian. H/X ratio: hygrophyte/xerophyte ratio.
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
The so-called Triassic-Jurassic Extinction(~202millionyearsago) killed off the big reptiles that up until then had ruled the planet, thus clearing the way for dinosaurs to take over. But why did dinosaurs thrive when other creatures died? The so-called Triassic-Jurassic Extinction(~202millionyearsago) killed off the big reptiles that up until then had ruled the planet, thus clearing the way for dinosaurs to take over. But why did dinosaurs thrive when other creatures died? Now a new study led by researchers from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and Columbia University answers this question. It reveals that Triassic dinosaur species—then a minor group largely relegated to the higher latitudes—regularly endured freezing conditions, suggesting they were well-adapted to the cold in a way that non dinosaurian species were not. Thus, when the Central Atlantic Magmatic Province (CAMP) caused years to decades of global volcanic winter at the end of the Triassic, dinosaurs were able to survive while then-dominant reptiles could not. The study was published in Science Advances on July 2. The researchers’ conclusion relied on two key findings: First, the researchers found physical evidence of dinosaur footprints from the Junggar Basin in Xinjiang Uygur Autonomous Region of northwestern China. During the Late Triassic to Early Jurassic, this region was located at about 71 degrees north, well above the Arctic Circle. The footprints showed that dinosaurs were present along shorelines. Second, when the researchers analyzed deep lake deposits, they found abundant pebbles up to about 1.5 centimeters in diameter within normally fine sediments. Far from any apparent shoreline, the pebbles had no business being there. That left only one plausible explanation: They were ice-rafted debris (IRD). Finding evidence of IRD was crucial to the study because it provided important climate clues. IRD is created when ice abuts a coastal landmass and incorporates bits of underlying rock as it freezes. At some point the ice becomes unmoored and drifts into the adjoining water body. When it melts, the rocks drop to the bottom, mixing with normally fine sediments. Geologists have extensively studied ancient IRD in the oceans, where it is deposited by glacial icebergs, but rarely in lake beds; the Junggar Basin discovery adds to the scant record. The researchers said the pebbles were likely picked up during winter, when lake waters froze along pebbly shorelines. When warm weather returned, chunks of ice floated away with pebbles in tow and later dropped them. “This shows that these areas froze regularly and the dinosaurs did just fine,” said study co-author Dennis Kent, a geologist at Columbia University’s Lamont-Doherty Earth Observatory. The researchers then used phylogenetic bracket analysis to conclude that the dinosaurs were primitively insulated with feathers. This insulation allowed them to adapt to intense volcanic winters and cold polar conditions so they could take advantage of the Arctic’s deciduous and evergreen vegetation. “The key to their eventual dominance was very simple. They were fundamentally cold-adapted animals. When it got cold everywhere, they were ready, and other animals weren't,” said Paul Olsen from Columbia University. While the end of the Triassic is often associated with deadly temperature spikes due to high carbon dioxide concentrations from volcanic eruptions, those same eruptions also deflected a great deal of sunlight, leading to volcanic winters. “Severe wintery episodes during volcanic eruptions may have brought freezing temperatures to the tropics, which is where many of the extinctions of big, naked, unfeathered vertebrates seem to have occurred,” said SHA Jingeng from NIGPAS. “Where as our fine feathered friends acclimated to colder temperatures in higher latitudes did okay.” After the biological extinction event at the end of the Triassic, dinosaurs rapidly increased in size and expanded their geographic range, with the total number of dinosaurs nearly doubling. From then on dinosaurs started their135-million-year-long terrestrial domination of Earth. Fig. 1 The supercontinent of Pangaea 202 million years ago, shortly before the Triassic-Jurassic Extinction. (Image by Olsen et al.)
Fig. 2 A shale cliff in the Junggar Basin in northwestern China, where scientists found ice-rafted pebbles amid otherwise fine-grained sediments. (Image by Paul Olsen)
Story Source: Materials provided by Columbia Climate School. Original written by Kevin Krajick. Note: Content may be edited for style and length. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
A research team has now conducted a study of yunnanozoans, extinct creatures from the early Cambrian period (518 million years ago), and discovered evidence that they are the oldest known stem vertebrates. The term stem vertebrate refers to those vertebrates that are extinct, but very closely related to living vertebrates. Scientists have long puzzled over the gap in the fossil record that would explain the evolution of invertebrates to vertebrates. Vertebrates, including fishes, amphibians, reptiles, birds, mammals, and humans, share unique features, such as a backbone and a skull. Invertebrates are animals without backbones. The process that moved invertebrates toward becoming vertebrates — and what those earliest vertebrates looked like — has been a mystery to scientists for centuries. A research team has now conducted a study of yunnanozoans, extinct creatures from the early Cambrian period (518 million years ago), and discovered evidence that they are the oldest known stem vertebrates. The term stem vertebrate refers to those vertebrates that are extinct, but very closely related to living vertebrates. The research team, from Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, and the Nanjing University, published their findings in the journal Science on July 8, 2022. Across the years, as scientists have studied how vertebrates evolved, a key focus of research has been the pharyngeal arches, those structures that produce parts of the face and neck, such as the muscles, bone, and connective tissue. Researchers have hypothesized that the pharyngeal arch evolved from an unjointed cartilage rod in vertebrate ancestors, such as the chordate amphioxus, a close invertebrate relative of the vertebrates. But whether such anatomy actually existed in the ancient ancestors has not been known for certain. In an effort to better understand the role of the pharyngeal arch in ancient vertebrates, the research team studied the fossils of the soft-bodied yunnanozoans found in the Yunnan Province, China. For years, researchers have studied the yunnanozoans, with differing conclusions on how to interpret the creature’s anatomy. The affinity of yunnanozoans has been debated for around three decades, with multiple papers published supporting varying opinions, including four in Nature and Science. The research team set out to examine newly collected yunnanozoan fossil specimens in previously unexplored ways, conducting a high-resolution anatomical and ultrastructural study. The 127 specimens they studied have well-preserved carbonaceous residues that allowed the team to conduct ultrastructural observations and detailed geochemical analyses. The team applied X-ray microtomography, scanning electron microscopy, transmission electron microscopy, Raman spectrometry, Fourier-transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy on the fossil specimens. Their study confirmed in multiple ways that yunnanozoans have cellular cartilages in the pharynx, a feature considered specific to vertebrates. The team’s findings support that yunnanozoans are stem vertebrates. The results of their study show that the yunnanozoans are the earliest and also the most primitive relatives of crown-group vertebrates. During their study, the team observed that all of the seven pharyngeal arches in the yunnanozoan fossils are similar to each other. The all arches have bamboo-like segments and filaments. Neighboring arches are all connected by dorsal and ventral horizontal rods, forming a basket. A basket-like pharyngeal skeleton is a feature found today in living jawless fishes, such as lampreys and hagfishes. "Two types of pharyngeal skeletons—the basket-like and isolated types—occur in the Cambrian and living vertebrates. This implies that the form of pharyngeal skeletons has a more complex early evolutionary history than previously thought," said Qingyi Tian, the first author of the study, from Nanjing University and Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences. Their research provided the team with new insights into the detailed structures of the pharyngeal arches. The new anatomical observations the team achieved in their study, support the evolutionary placement of yunnanozoans at the very basal part of the vertebrate tree of life. The research team includes Qingyi Tian from Nanjing University (NJU) and Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS); Fangchen Zhao and Han Zeng from NIGPAS; Maoyan Zhu from NIGPAS and the University of Chinese Academy of Sciences; and Baoyu Jiang from NJU. The Strategic Priority Research Program (B) of the Chinese Academy of Sciences and the National Science Foundation of China funded this research. Reference: Qingyi Tian, Fangchen Zhao*, Han Zeng, Maoyan Zhu, Baoyu Jiang*, 2022. Ultrastructure reveals ancestral vertebrate pharyngeal skeleton in yunnanozoans. Science, 377(6602), https://www.science.org/doi/10.1126/science.abm2708.
Caption: Artistic reconstruction of the yunnanozoan from the Cambrian Chengjiang biota shows basket-like pharyngeal skeletons (Drawn by Dinghua Yang). Credit: Fangchen Zhao, NIGPAS
Caption: The stem vertebrate yunnanozoan. Credit: Fangchen Zhao, NIGPAS
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Abundant rudist bivalves have been reported from the Yigeziya Formation, most of them were considered as endemic taxa that were restricted to central Asia including Tajik, Fergana, Alai and Tarim basins. During Cretaceous to Paleogene, a shallow epicontinental sea extended across Eurasia from the Mediterranean Tethys to the southwestern Tarim Basin, and its eastern extremity being referred to as the Tarim Sea, which was commonly regarded as a branch of the Neotethys. During Late Cretaceous, two distinct transgressive events have been identified in Tarim Sea: the first is represented by the deposition of early Cenomanian to Turonian Kukebai Formation, and the second formed the Campanian to early Maastrichtian Yigeziya Formation. Abundant rudist bivalves have been reported from the Yigeziya Formation, most of them were considered as endemic taxa that were restricted to central Asia including Tajik, Fergana, Alai and Tarim basins. Biradiolites minor Pojarkova, described by Lan and Wei (1995) from the middle member of the Yigeziya Formation, is characterized by the glabrous outer shell layer except for four salient ridges on the shell margin of the right valve. This feature is inconsistent with the genus Biradiolites d’Orbigny which is normally ornamented with strongly protruding longitudinal ridges over the whole right valve. Recently, Dr. RAO Xin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and her colleagues re-studied the species B. minor based on the published and new specimens, transferred it to the genus Glabrobournonia according to the taxonomic re-examination. Glabrobournonia is a genus of radiolitids characterized by indented radial bands, salient ridges on the shell margins and absence of fine ribs on the surface of the right valve. Apart from southwestern Tarim Basin, Glabrobournonia minor (Pojarkova) has also been recorded from the late Campanian of Fergana and Alai basins. The central Asian, late Campanian to early Maastrichtian G. minor differs from the late Campanian to Maastrichtian, eastern Arabian type species Glabrobournonia arabica Morris and Skelton in the flat left valve and an additional fourth ridge on the junction of the dorsal and posterior sides of the right valve. Biradiolites ingens (Des Moulins) could be the direct ancestor of Glabrobournonia. The paleogeographic distribution of Glabrobournonia suggests that this genus dispersed to central Asia from the late Campanian time, becoming widely distributed in the eastern Tethyan region rather than endemic to eastern Arabia. Correspondingly, specimens belonging to Gyropleura yielded from the same bed as G. minor in southwestern Tarim Basin, are similar to the specimens which were attributed to the eastern Arabian Gyropleura sp.; Campanian to early Maastrichtian Osculigera specimens described from the Yigeziya Formation are comparable with those known from the Campanian–Maastrichtian of Iran, Afghanistan and eastern Arabia. The similarity of the rudist assemblages between central Asia and eastern Arabia suggests a faunal connection and affinity between the north and south margins of the eastern Tethyan realm during Campanian to early Maastrichtian times. This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, the National Natural Science Foundation of China, and the State Key Laboratory of Palaeobiology and Stratigraphy, Chinese Academy of Sciences. Reference: X. Rao, P. W. Skelton, S. Sano et al., Taxonomy and paleobiogeographic implication of Glabrobournonia Morris and Skelton (Hippuritida, Radiolitidae) from the Late Cretaceous Yigeziya Formation, southwestern Tarim Basin, Palaeoworld, https://doi.org/10.1016/j.palwor.2022.05.003. Fig. 1. (a) Map of the southwestern Tarim Basin and adjacent basins bearing Late Cretaceous rudists. (b) Geologic map showing the fossil locality in southwestern Tarim Basin. (c) Stratigraphic column of the Yigeziya section and the occurrence of Glabrobournonia minor within the section. Fig. 2. Glabrobournonia minor (Pojarkova) from the Yigeziya Formation of the Yingjisha County, southwestern Tarim Basin. Scale bar represents 10 mm. Fig. 3. Paleogeographic map of late Campanian showing the reconstructed situations of the fossil localities bearing Glabrobournonia (base map after Scotese, 2014). Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Resource pulses, occasional events of ephemeral resource superabundance, represent a fundamental mechanism by which energy, nutrients, and biomass are transported across ecotones. They are widespread in extant ecosystems; however, little is known about their deep-time record. Resource pulses, occasional events of ephemeral resource superabundance, represent a fundamental mechanism by which energy, nutrients, and biomass are transported across ecotones. They are widespread in extant ecosystems; however, little is known about their deep-time record. Recently, ZHANG Qianqi, a PhD student from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Profs. WANG Bo and ZHANG Haichun, in collaboration with other researchers carried out a detailed investigation of early Mesozoic terrestrial strata in several regions in southern China. The researchers discovered abundant marine and terrestrial animal and plant fossils in the Lower Jurassic Shiti Formation in the Xiwan Basin of Hezhou City, Guangxi Province, China. Researchers report the earliest-known mayfly swarm from the Early Jurassic Xiwan biota of southern China, and the results were published in the journals Geology and Historical Biology. The Mesozoic study in the Xiwan Basin has a long history, and both Profs. SZE Hsing-Chien and ZHOU Zhiyan had ever studied the plant fossils from Xiwan, among which plenty of insect fossils from the Shitian Formation were reported by Prof. LIN Qibin. "We recently found abundant new insects, plants, and shark egg capsules from a new fossil locality. In view of the abundance of the diverse insects and plants, we propose that the fossil assemblage in the lower unit of the Shiti Formation be named the Xiwan biota, which is among the richest Jurassic biotas in China", ZHANG Qianqi says. This research team found one fossil layer with hundreds of mayflies in the lower unit of the Shiti Formation. These mayflies were classified as a new taxon, Jurassephemera zhangi Zhang et al. (2022), which is assigned to the extinct family Sharephemeridae, a stem group mayflies in terms of taxonomic position. This is the first discovery of the mayfly family in China, and is the best preserved fossil of the family. "We measured the orientations of 381 mayflies and found that these mayflies do not show any obvious directionality, although the rose diagram suggests a south westerly trend perhaps reflecting the effect of a slight movement of the bottom water after accumulation of the carcasses", says ZHANG. Furthermore, all the mayflies are complete with body, appendages, and wings attached, which, when taken with the above, indicates that the mayflies were not transported any significant distance in the water after death and were buried in a low-energy preservational environment. Extant mayflies spend most of their life in the aquatic environment as nymphs, and the adults commonly live from as little as 1–2 hours to a few days. During their short adult phase, the males form dense aggregations, and the females must find mating partners while flying in and through large swarms, wherein they copulate and ultimately locate a suitable place to deposit eggs. Mating-swarm behavior was previously known only in crown mayflies; however, our find reveals that such complex behaviors were already well established in stem-group mayflies by the Early Jurassic. "And this finding represents the earliest evidence of mating-swarm behavior in insects", ZHANG says. Using elemental energy spectroscopy and Raman component analysis, the results show that the outermost layer of the fossils of the Xiwan biota is mainly iron oxides and clay mineral residues, but the surface composition of the fossils is still dominated by carbon elements. The researchers conclude that the iron oxide covering of the fossil surface was formed during the diagenetic process later and likely formed during the weathering process. Aquatic insects play an important role in aquatic food webs, acting as consumers of aquatic plants and animals, and they are in turn consumed by fish and other predators. But aquatic insects can also be important parts of food webs on land when they emerge as adults from the water and fly to disperse and find mates. In addition to providing food bonanzas for predators, emerging insects can also have a fertilizing effect on plant communities next to lakes and streams when they die and decompose. This study shows that some Jurassic mayflies emerged all at once in large swarms, which is a “pulse” of insects moving from the water to land, probably resulting in massive ecosystem fluxes in waterside habitats with impacts on basic ecology and biogeochemical cycling. Such a mechanism that can play a substantial role in nutrient transport from aquatic ecosystems to surrounding terrestrial ecosystems, while this aquatic-terrestrial ecosystem linkage may be a key novelty in Mesozoic lacustrine ecosystems. "Therefore, our finding highlights the underappreciated ecological significance of insects in short-lived feeding bonanzas and mass mortalities in deep-time lacustrine ecosystems." ZHANG added. This research was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Zhang Qianqi, Wang Bo*, Zheng Daran, Li Jiahao, Wang Xueheng, Jarzembowski E.A., Xu Chunpeng, Li Ting, Zhang Haichun, Engel M.S. 2022. Mayflies as resource pulses in Jurassic lacustrine ecosystems. Geology. https://doi.org/10.1130/G50055.1. Zhang Qianqi*, Zheng Daran, Jarzembowski E.A., Wang Xueheng, Li Jiahao, Engel M.S. 2022. The first Sharephemeridae (Insecta: Ephemeroptera) from the Jurassic Shiti Formation of South China. Historical Biology. https://doi.org/10.1080/08912963.2022.2077649. Figure 1: Three pieces of fossil surface with mayfly swarms from the Shiti Formation in southern China. All are the same scale and orientation. Figure 2: Sedimentology (A–D) and taphonomy (E–L) of the fossil-bearing layer from the Shiti Formation in southern China. Figure 3: Reconstruction of the Early Jurassic ecosystem of the Xiwan Basin (designed by YANG Dinghua, NIGPAS).
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
What would happen in the near future with continued global warming? What environmental conditions would the life on Earth most likely confront? The episodes of climate changes in the Earth’s deep past, similar to the current global warming, may provide valuable clues to these questions. What would happen in the near future with continued global warming? What environmental conditions would the life on Earth most likely confront? The episodes of climate changes in the Earth’s deep past, similar to the current global warming, may provide valuable clues to these questions. A recent study led by scientists from China, U.S., and New Zealand reveals that an abrupt warming linked to massive carbon emission during an icehouse climate state caused approximately 20% of anoxic areal extent of the seafloor, and significant biodiversity drop. The finding was published by the Proceedings of the National Academy of Sciences of the United States of America on May 2, 2022. As is known, we are currently living under the Cenozoic icehouse climate that has started since 34 Myr ago. However, global temperature rises rapidly under this icehouse over a couple of centuries, in tandem with accelerated ablation of polar glaciers, rising sea-level, and aggravating marine de-oxygenation, and undoubtedly leading to a significant drop in biodiversity. Where would the global warming lead us to in the future? There are substantial uncertainties regarding the modeling results based on current observations, which drive the current focus on understanding past episodes of carbon emission and ocean deoxygenation, particularly under an icehouse climate state. The Late Paleozoic Ice Age (LPIA, between 360 and 280 million years ago) is the longest-lived and the only icehouse that recorded the transition from icehouse to greenhouse climate states since the occurrence of advanced plants and terrestrial ecosystem. The LPIA is also the only geological period that is featured by low atmospheric CO2 and high O2 concentrations, highly comparable to those of the modern day. It is, therefore, critical to study carbon emissions and their consequences during the LPIA for better understanding the processes and feedbacks of the icehouse Earth system, and thus for more precisely predicting the future environmental and biodiversity changes. A international research team led by Dr. CHEN Jitao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Dr. WANG Xiangdong from the Nanjing University, and Dr. Isabel P. Montanez from the University of California, Davis studied the Carboniferous strata from the southern China for over 10 years, with respect to sedimentology, stratigraphy, paleontology, and geochemistry. The Naqing and Narao sections from the Luodian region, Guizhou Province crop out continuous Carboniferous carbonate successions that register geochemical signal of sea water. Scientists collected samples by every 20 cm for over 40-m-thick strata from the two sections and carried out carbon and uranium isotopes to explore the global carbon cycling and marine anoxia. "We utilized global carbon cycle model (LOSCAR) and paleo carbon dioxide concentrations to simulate a total amount of 9,000 Gt C emitted over 300 kyr, causing an increase in sea-surface temperature by ~4℃", CHEN says. "We also modelled an increase in areal extent of the anoxic seafloor from 4% to 22%, causing a dramatic decrease in biodiversity" CHEN Added, "and finally, we performed climate model simulations using the fully coupled Community Earth System model (CESM) to explore the potential mechanisms for the marine anoxia, which are linked to enhanced thermocline stratification and increased nutrient fluxes during the warming." The study further finds that warming-induced marine anoxia may be more pronounced in a glaciated than in an unglaciated period. Reference: Chen, J.T., Montanez, I.P., Zhang, S., Isson, T.T., Macarewich, S.I., Planavsky, N.J., Zhang, F., Rauzi, S., Daviau, K., Yao, L., Qi, Y.P., Wang, Y., Fan, J.X., Poulsen, C.J. Anbar, A.D., Shen, S.Z., Wang, X.D., 2022. Marine anoxia linked to abrupt global warming during Earth’s penultimate icehouse, PNAS, https://doi.org/10.1073/pnas.2115231119. Fig. 1. An abrupt global warming occurred at ~304 Ma under the Carboniferous icehouse climate state, consistent with doubling of atmospheric carbon dioxide, significant negative excursion in carbon isotopes, sea-surface temperature increase, and drop in biodiversity. Fig. 2. Carbon and uranium isotopes recorded in the Naqing section, Guizhou Province, southern China, showing remarkable negative excursions across the Kasimovian-Gzhelian boundary. Modeling results suggest a distinct perturbation in global carbon cycle and an increase in marine anoxia. Fig. 3. Comparison between the KGB warming event during the late Carboniferous icehouse and greenhouse C-perturbation events over the last 300 Myr, indicating that the KGB warming had a more extreme impact on the marine redox landscape relative to its rate of C injection and SST increase than the other events. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Assembly of Gondwana commenced in the Neoproterozoic with final disassembly of the supercontinent completed by the Cretaceous. The configuration of major continental blocks (e.g., India, Australia, East Antarctica, and Africa) of Gondwana has been well reconstructed. However, paleopositions of some small continental fragments along the periphery of Gondwana are still in controversy. Assembly of Gondwana commenced in the Neoproterozoic with final disassembly of the supercontinent completed by the Cretaceous. The configuration of major continental blocks (e.g., India, Australia, East Antarctica, and Africa) of Gondwana has been well reconstructed. However, paleopositions of some small continental fragments along the periphery of Gondwana are still in controversy. The Baoshan, Tengchong, Lhasa, South Qiangtang, and Sibumasu terranes were located along the northern margin of Gondwana before late Early Permian rifting. A substantial amount of work has been carried out, aiming at reconstructing the paleopositions of these terranes from various disciplines such as sedimentary provenance, paleomagnetism, and paleobiogeography. These studies led to various paleogeographic models of northeastern Gondwana. Recently, a paleogeographic study based on detrital zircon U-Pb ages and Hf isotopic values from Paleozoic strata of northeastern Gondwana, which is conducted by GAO Biao, his advisor Prof. CHEN Jitao, and Prof. QIE Wenkun from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with the scientist Prof. WANG Xiangdong from Nanjing University. Primary component analysis (PCA) was used to visualize the relative relationship between these terranes and East Gondwana, in addition with the glacier distribution pattern on northeastern Gondwana in the late Paleozoic. The research achievements were published in the international journal Sedimentary Geology. Based on a total of 8209 detrital zircon U-Pb ages and 1606 zircon Hf isotopic values from Paleozoic strata of northeastern Gondwana, a new paleogeographic model has been reconstructed. It indicates that the South Qiangtang, Baoshan, and part of Sibumasu were outboard of the northern margin of Indian Gondwana during the Paleozoic, whereas the Lhasa and Sumatra terranes were located along the northern margin of Australia. Based on provenance shifts of late Paleozoic glaciogenic sedimentary rocks in northeastern Gondwana, two main ice sheets are hypothesized to have developed during the late Paleozoic. This study further confirms the model of a multicenter glacier distribution pattern on Gondwana during the late Paleozoic ice age from a perspective of provenance. The research is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Second Tibetan Plateau Scientific Expedition and Researh Program. This is a contribution to IGCP 700 and DDE (Deep-time Digital Earth) projects. Reference: Gao, B.*, Chen, J.T.*, Qie, W.K., Wang, X.D., 2022. Revisiting the paleogeographic framework of northeastern Gondwana in the late Paleozoic: implications from detrital zircon analysis. Sedimentary Geology. Available online 11 April 2022. https://doi.org/10.1016/j.sedgeo.2022.106144. Schematic geological map of Southeast Asia and detrital zircon samples locations Primary component analysis (PCA) of detrital zircon characteristic age population
Reconstruction of northeastern Gondwana with regional ice centers during the late Paleozoic ice age Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
