Fossil woods preserved in deposits through the process of permineralization play a crucial role in reconstructing the floristics aspects of ancient forest ecosystems and climatic conditions in deep time. Fossil woods have been widely discovered in terrestrial ecosystems from the dinosaurs ages in the Jurassic and Cretaceous. In China, the fossil woods are mainly documented in the northern China region; however, the records in southern China are relatively poor. Fossil woods preserved in deposits through the process of permineralization play a crucial role in reconstructing the floristics aspects of ancient forest ecosystems and climatic conditions in deep time. Fossil woods have been widely discovered in terrestrial ecosystems from the dinosaurs ages in the Jurassic and Cretaceous. In China, the fossil woods are mainly documented in the northern China region; however, the records in southern China are relatively poor. Recently, a new extinct species of conifer wood dated over 100 million years, i.e. Brachyoxylon zhoui was reported by a research team lead by Prof. WANG Yongdong at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Dr. JIANG Zikun at the Chinese Academy of Geological Sciences, in conjunction with the other researchers at the Zhejiang Museum of Natural History, Shenyang Normal University, and University of Bonn in Germany. This finding was recently published in the international journal Historical Biology. The fossil wood specimen was found in the Early Cretaceous Guantou Formation (about 110 Ma) in Yongkang City of Zhejiang Province, which is anatomically different from any reported fossil woods in Zhejiang. Based on comparisons between the present fossil wood material and other relative fossil woods worldwide, a new species of the morphogenus Brachyoxylon, i.e. Brachyoxylon zhoui was established by the research team. The specific name zhoui is dedicated to Prof. ZHOU Zhiyan from Nanjing for his contributions to Palaeonbotany. The terrestrial sediments, largely deposited during the Early Cretaceous in Zhejiang, contain vertebrate fossils, such as dinosaur bones and eggs, and additionally yield abundant fossil woods. The new fossil wood material is silicified and part of the secondary xylem of the tree. The new species is characterized by distinct growth rings, a mixed type of radial tracheary pitting, araucarioid cross-field pitting, high uniseriate rays, and traumatic resin canals. The quantitative analysis of the growth ring was carried out by researchers, indicating that the forest composition was evergreen with a Leaf Retention Time (LRT) of 3–15 years. Combined with the analysis of sedimentology, palynology and paleosols, researchers assume that the Zhejiang region was dominated by a subtropical to tropical and relatively semiarid climate during the Early Cretaceous. The discovery of Brachyoxylon zhoui not only enriches the understanding of the fossil forest composition and paleoclimate but also provides the essential evidence to reconstruct the paleohabitats of dinosaurs in the Early Cretaceous of Zhejiang Province. The study was co-corresponded by Dr. JIANG Zikun at the Chinese Academy of Geological Sciences and Prof. WANG Yongdong at the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, other co-authors include Dr. WU Hao at the Zhejiang Museum of Natural History, Associate Professor TIAN Ning at the Shenyang Normal University, and Ph.D. candidate XIE Aowei at the University of Bonn in Germany. This research was co-supported by the National Natural Sciences Foundation of China, the Strategic Priority Program (B) of CAS, the State Key Program for Basic Research & Development of Ministry of Science & Technology of China and the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS). Reference: Jiang Zikun*, Hao Wu, Ning Tian, Yongdong Wang*, Aowei Xie, 2020. A New Species of Conifer Wood Brachyoxylon from South China and its Palaeoclimatic Implications. Historical Biology, https://doi.org/10.1080/08912963.2020.1755282 The anatomical structures of growth rings, radial tracheary pitting in fossil conifer wood Brachyoxylon zhoui from the Early Cretaceous in Zhejiang Province of China The anatomical structures of cross-field pitting and xylem rays in fossil conifer wood Brachyoxylon zhoui from the Early Cretaceous in Zhejiang Province of China The quantitative analysis of the growth ring and paleoclimate of fossil conifer wood Brachyoxylon zhoui from the Early Cretaceous in Zhejiang Province of China
Trace fossils are the behavioural records of ancient organisms, representing the archives of the interactions between organisms and their living substrates. As a special kind of fossil types, trace fossils may include trails, tracks, burrows and feces excreted by animals (coprolites). Trace fossils are the behavioural records of ancient organisms, representing the archives of the interactions between organisms and their living substrates. As a special kind of fossil types, trace fossils may include trails, tracks, burrows and feces excreted by animals (coprolites). The trace makers may include both skeletonized as well as soft-bodied organisms. Soft bodied organisms normally are seldom to be preserved as fossils. Hence trace fossils potentially provide more complete records of both infaunal and epifaunal organisms, thus facilitating the study of community structures and composition of ancient ecosystems. These characteristics make trace fossils as ideal agents to explore the evolution of early life on Earth, infaunal responses to environmental extremes during mass extinctions, palaeoenvironmental interpretations, and characterization and recognition of significant stratigraphical boundaries in petroleum geology. Recently, Dr. LUO Mao from Nanjing Institute of Geology and Palaeontology , Chinese Academy of Sciences (NIGPAS) collaborated with Prof. SHI Guangrong and Dr. Lee Sangmin from University of Wollongong, Australia, had discovered a new trace fossil assemblage dominated by a potential bivalve trace (Parahaentzschelinia) from the Lower Permian Snapper Point Formation, which records deposition in a storm-influenced delta front environment. Related research results have been published in Palaeogeography Palaeoclimatology Palaeoecology. The dense populations of Parahaentzschelinia trace occurred in two sections, forming stacked Parahaentzschelinia ichnofabrics. Researchers interpreted these ichnofabrics as equilibrium structures, which reflect the trace maker actively adjust their living positions in response to the shifted sediment-water interface, in seeking to remain in an optimal (equilibrium) living position with the local hydrodynamic and depositional conditions (e.g., increased sedimentation or periodic erosion). The trace Parahaentzschelinia is an irregular, funnel-shaped burrow with multiple mud and sand-filled tubes radiating vertically or obliquely upward to the sediment surfaces. Distinct meniscate fills composed of alternating sand and mud laminae are characteristic of nearly all tubes, which are superimposed laterally and vertically. These dense, irregular funnel-shaped burrows may be produced by tellinid-like bivalves based on observations on the metabolic behaviour and burrow morphologies of modern tellinids. According to Dr. LUO Mao, the meniscate fills in Parahaentzschelinia isp. may be the result of successive movements of the siphons, leaving alternating sand and mud laminae. Statistical analysis of burrow lengths and numbers of burrow adjustments suggests up to seven sequences of sediment accumulation events, supplying 3–13 cm thick clastic deposits at each time. A conservative sedimentation rate of 0.24 cm/year was estimated on the basis of two stacked Parahaentzschelinia ichnofabrics and the probable maximum lifespan of modern tellinid genus. This rate is generally comparable to those derived from modern deltaic environments, lending further support to the interpretation that the ichnofabrics were formed in and characteristic of a deltaic setting. The research highlights the utility of stacked equilibrium structures as a sensitive indicator of certain depositional regimes, and its applicability for assessing sedimentation rates as well as depositional conditions in the geological past. The research has been jointed supported by the Strategic Priority Research Program of Chinese Academy of Sciences, the CAS Talents Program, the National Natural Science Foundation of China, and an Australian Research Council. Reference: Luo M*., Shi, G.R*., Lee, S., 2020, Stacked Parahaentzschelinia ichnofabrics from the Lower Permian of the southern Sydney Basin, southeastern Australia: Palaeoecologic and palaeoenvironmental significance. Palaeogeography, Palaeoclimatology, Palaeoecology 541, 109538. doi.org/10.1016/j.palaeo.2019.109538 Intergated section logs of the studied sections at Pretty Beach south (left) and O’Hara Island (right), which both represent the lower part of the Snapper Point Formtion in the southern Sydney Basin Densely occurred Parahaentzschelinia from the section at O’Hara Island. A, Parahaentzschelinia isp. recording sequence of event sedimentation layers. Black arrows indicate individual Parahaentzschelinia isp.. B, Schematic artwork showing the re-adjustments of Parahaentzschelinia to episodic sediment deposition in A
The end-Permian Mass Extinction (EPME) is widely considered to record the largest biodiversity loss coupled with the most severe ecological impact in Earth history. More than 90% of the marine species were killed in less than 200 000 years. In the aftermath of this catastrophe, the Early Triassic was characterized by large, frequent fluctuations in carbon isotopes, extremely high sea-surface temperatures, and widespread anoxic conditions, and even oceanic acidification in the global oceans. The subsequent marine biotic recovery in the Early Triassic has been delayed for a prolonged interval of around 6 million years due to persistent warming and anoxia. The end-Permian Mass Extinction (EPME) is widely considered to record the largest biodiversity loss coupled with the most severe ecological impact in Earth history. More than 90% of the marine species were killed in less than 200 000 years. In the aftermath of this catastrophe, the Early Triassic was characterized by large, frequent fluctuations in carbon isotopes, extremely high sea-surface temperatures, and widespread anoxic conditions, and even oceanic acidification in the global oceans. The subsequent marine biotic recovery in the Early Triassic has been delayed for a prolonged interval of around 6 million years due to persistent warming and anoxia. Studying the biotic recovery after the biggest mass extinction would help us understand the responses and evolutionary mechanism of ecosystems through extreme environmental changes, but also give implications to the management of modern marine ecosystems under global environmental change as those abovementioned environmental extremes are adversely affecting the livelihood of marine organisms. The impact of the EPME on behavioural aspects of the infauna, as reflected in the global abundance and diversity of trace fossils, is less explored. In many instances, trace fossils represent the behavioural records of soft-bodied organisms that have null to very limited preservation in the fossil record. They often supply vital ecological information on ancient communities not available from body-fossil documentations. In order to better understand the behavioural responses of trace makers to environmental perturbations, Dr. LUO Mao and his collaborators including Prof. Luis A. Buatois from University of Saskatchewan, Prof. SHI Guangrong from University of Wollongong, and Prof. CHEN Zhongqiangfrom China University of Geosciences (Wuhan) has compiled a global Permian？Triassic trace-fossil database. The research aims to give a comprehensive review of long-term ichnodiversity and ichnodisparity changes following the EPME, and assess how infaunal organisms behaved in response to the extinction crisis and during the biotic recovery intervals. The results have been published online in the GSA Bulletin, an international comprehensive geology journal. The study, led by Dr. LUO Mao, has depicted the global ichnodiversity and ichnodisparity change from late Permian to Middle Triassic comprising twelve time slices. Importantly, they found that global ichnodiversity and ichnodisparity maintained their pre-extinction level after the end-Permian mass extinction. In particular, late Permian global ichnodiversity and ichnodisparity maintained their level until the Griesbachian, followed by a sharp loss in the Dienerian stage. This result in diversity of trace fossils is in contrast to that of body fossils. A further analysis of the tiering composition of ichnogenera from each time slices showed that Early Triassic trace fossils are dominated by shallower tiered ichnogenera when compared with pre- and post-extinction trace fossil compositions. Furthermore, such difference in tier composition is statistically obvious. Dr. LUO Mao and his collaborators interpreted that such global ichnodiversity change might have be a taphonomic effect caused by the wide-spread occurrence of microbial mat substrate during the Early Triassic. The development of firm substrates enhanced by microbial mat enveloping, aiding the preservation of shallow-tiered trace fossils, and maintaining the high ichnodiversity level in the earliest Triassic. The dataset, and the ichnodiversity trends revealed by Dr. LUO Mao and his collaborators suggested that the high ichnodiversity and ichnodisparity in the earliest Triassic is best explained as a taphonomic artifact. The sustained high ichnodiversity in the Griesbachian, combined with the preferential occurrence of shallow-tier bioturbation structures suggests limited mixing of seafloor sediments, which have drawn parallels with substrate conditions proposed for Ediacaran-Fortunian strata. The research has been jointed supported by the Strategic Priority Research Program of Chinese Academy of Sciences, the CAS Talents Program, and the National Natural Science Foundation of China. Reference: Luo, M*., Buatois, L.A., Shi, G.R., Chen, Z.Q., 2020. Infaunal response during the end-Permian mass extinction. https://doi.org/10.1130/B35524.1. Line chart diagram summarizing variation in global ichnodiversity (a) and ichnodisparity (b) in comparison with the global generic richness of body fossils (c) Change in ichnofossil tiering levels from late Permian to Middle Triassic expressed as area plots Box plots comparing the percentage of different tiering groups between Early Triassic and pre- (late Permian) and post-extinction (Middle Triassic) intervals General trend of relative abundance of microbialites in the Lower–Middle Triassic
Trace fossils, as behavioural records of organisms in the geological past, have been proved useful in deciphering the mechanisms and timing of biotic recovery after mass extinctions. In many cases, trace fossils record the behaviours of soft-bodied organisms that have null to very limited preservation potential in the fossil record. They often provide significant ecologic information on ancient communities not available from the study of body fossils. Trace fossils, as behavioural records of organisms in the geological past, have been proved useful in deciphering the mechanisms and timing of biotic recovery after mass extinctions. In many cases, trace fossils record the behaviours of soft-bodied organisms that have null to very limited preservation potential in the fossil record. They often provide significant ecologic information on ancient communities not available from the study of body fossils. More and more ichnologists focused on ichnological records during mass extinctions and subsequent biotic recovery intervals, with numerous studies emphasizing ichnological proxies as indicators of biotic recovery process after the latest Permian, when the the end-Permian mass extinction (EPME) has caused the highest biodiversity loss coupled with the most profound ecological impact in Phanerozoic Earth history. The vast majority of ichnological studies have focused on elucidating the timing and patterns of ecosystem recovery after the EPME, leading to the establishment of various ichnological parameters (e.g., ichnodiversity, bioturbation indices, bedding plane bioturbation indices, burrow sizes, tiering, trace-fossil complexity) as proxies for unraveling the pacing and processes of biotic recovery in the Early Triassic. However, some recognitions derived from ichnological studies seem to be inconsistent with those from body fossil observations (prolonged, stepwise recovery versus fast recovery). In addition, there are also cases whereby different ichnologists choose to use different parameters (e.g., ichnofabric indices and bioturbation indices) for documenting the same ichnological features. These discrepancies pose a need to critically evaluate current and popular ichnological parameters and the scopes of their applicability. Recently, Dr. LUO Mao from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) in collaboration with Prof. SHI Guangrong from University of Wollongong (Australia), Prof. Buatois from University of Saskatchewan (Canada), and Prof. CHEN Zhongqiang from China University of Geoscience (Wuhan) presented a critical review on the use of various ichnological parameters as relative proxies for unravelling ecosystem recovery after the EPME in order to place them on more solid theoretical grounds. In their study, the significance and caveats of various ichnological parameters and their limitations are clarified and discussed in detail, in the hope that these proxies will be more appropriately used in the future studies dealing with mass extinctions and biotic recoveries. Related research results has been published online in the comprehensive geology journal Earth-Science Reviews. According to Dr. LUO Mao, ichnodiversity, ichnodisparity, burrow sizes are good indicators of biotic recovery, while bedding plane bioturbation indices remain to be explored further as various studies suggest that on bedding planes, trace-fossil distribution can be heterogeneous on a scale of meters to decimeters. In terms of tiering, the composition of the different tiers (e.g., shallow, intermediate, and deep tier) should be reconstructed rather than only considering the penetration depth of burrows. Further, it is worth noting that evaluating the benthic ecospace occupation and ecosystem engineering through the analysis of trace fossils would be a promising approach. Based on current ichnological studies from the Permian-Triassic interval and researchers own observations, Dr. LUO Mao and his collaborators have reached several main recognitions for biotic recovery after the end-Permian mass extinction. These are: (1) Distribution of varying oxic conditions results in the disparate patterns of benthic macrofaunal recovery (including trace-making organisms) in the Early Triassic. Such oxic conditions in the shallow-marine ‘habitable zone’ possibly aid a faster recovery of trace-making organisms in the earliest Triassic. (2) The widespread matground-dominated ecosystems could have inhabited a variety of metazoans (including trace makers) during the Earl Triassic recovery interval. (3) Low bioturbation intensities in the Lower Triassic strata may be a reason leading to enhanced pyrite burial and prolonged low sulfate concentrations in the Early Triassic ocean. This research has been supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the CAS Pioneer Hundred Talents Program, and by grants from NSFC. Reference: Luo, M*., Shi, G.R., Buatois, L.A., Chen, Z.Q., 2020. Trace fossils as proxy for biotic recovery after the end-Permian mass extinction: A critical review. Earth-Science Reviews, Volume 203, 103059. Trend of ichnodiversity along a depositional profile (modified from Buatois and Mángano, 2013)
Trend of burrow-size changes for typical ichnotaxa (Planolites, Rhizocorallium, Thalassinoides) from Permian to Middle Triassic (global data) Tiering structure as expressed by the maximum penetration depth and ichnological composition at different sediment depths
Integrated marine geochemical variations and general bioturbation intensity during the Permian-Triassic interval, with geochemical cycling models established for the Late Permian, Early Triassic, and Middle Triassic respectively
Ordovician corals in eastern Australia are mostly confined to the Upper Ordovician series, with the earliest tabulates occurring in strata which span the uppermost Darriwilian (upper Middle Ordovician) to basal Sandbian (lower Upper Ordovician) interval. Recognition of the biostratigraphic utility of coral faunas in the field as an adjunct to mapping Ordovician limestones in NSW led previous authors to propose a series of four coral/stromatoporoid faunas: C/S I–IV from oldest (Eastonian 1, equivalent to latest Sandbian–earliest Katian) to youngest (Bolindian 1–2, or latest Katian). Such a local biostratigraphic framework permits an accurate means of dating field collections in the region, and has also enhanced our understanding of the evolutionary history of corals and stromatoporoids during this time interval. Ordovician corals in eastern Australia are mostly confined to the Upper Ordovician series, with the earliest tabulates occurring in strata which span the uppermost Darriwilian (upper Middle Ordovician) to basal Sandbian (lower Upper Ordovician) interval. Recognition of the biostratigraphic utility of coral faunas in the field as an adjunct to mapping Ordovician limestones in NSW led previous authors to propose a series of four coral/stromatoporoid faunas: C/S I–IV from oldest (Eastonian 1, equivalent to latest Sandbian–earliest Katian) to youngest (Bolindian 1–2, or latest Katian). Such a local biostratigraphic framework permits an accurate means of dating field collections in the region, and has also enhanced our understanding of the evolutionary history of corals and stromatoporoids during this time interval. Corals representing the sole occurrence of C/S Fauna IV of the regional biostratigraphic scheme occur in limestone in the uppermost Malachis Hill Formation of the Bowan Park area, central New South Wales. Though this coral fauna is restricted to a relatively thin limestone band, exposed intermittently for approximately 1.5 km, its significance greatly outweighs this in terms of completing the coral biostratigraphic scheme and also in contributing to the knowledge of the biogeographic relationships of the region in the Late Ordovician. Recently, Dr. WANG Guangxu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and his colleagues Ian. G. Percival and ZHEN Yong Yi from Geological Survey of New South Wales described corals from the uppermost Malachis Hill Formation in central NSW. Related research results have been published online in the international geoscience journal Alcheringa. New species described and illustrated from this fauna include the rugosan Bowanophyllum ramosum and tabulate Hemiagetiolites longiseptatus. Also three other distinct species of Hemiagetiolites, H. spinimarginatus (Hall, 1975), H. cf. H. palaeofavositoides (Lin & Chow, 1977) and H. sp., an unnamed species of Paleofavosites, and three heliolitine corals, Heliolites waicunensis Lin & Chow, 1977, Navoites cargoensis (Hill, 1957) and Plasmoporella sp. were documented. These descriptions, which complete knowledge of the entire fauna collected over 50 years, enable interesting conclusions to be drawn regarding palaeogeographic affinities of this youngest in situ Ordovician coral fauna known from eastern Australia. Its remarkable similarities to contemporaneous coral faunas from South Tien Shan and the Chu-Ili Terrane indicate strong connections between eastern Australia and the latter two terranes, supporting their positioning in equatorial latitudes of eastern peri-Gondwana. However, it is puzzling that fewer similarities exist between the eastern Australian coral fauna and those from rocks of Katian age in SE China, which may be due to either a slightly younger age of the former fauna or a relatively higher palaeolatitudinal position of South China. This research was jointly supported by the National Science Foundation of China, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences. Reference: Wang, G. X., Percival, I. G. & Zhen, Y. Y., 2020. The youngest Ordovician (latest Katian) coral fauna from eastern Australia, in the uppermost Malachis Hill Formation of central New South Wales. Alcheringa (https://doi.org/10.1080/03115518.2020.1747540) A new rugose coral Bowanophyllum ramosum documented from the Malachis Hill Formation of central New South Wales, eastern Australia
Cordaitaleans, as close relatives of modern conifers, had a long geological history in the Cathaysia from the Visean (Mississippian, lower Carboniferous) to the end of Permian. They became prominent since the late Pennsylvanian, and best developed during the Cisuralian (early Permian) in North China, serving as the volumetrically dominant to subdominant elements of wetland floras. Architecture and ecology of the Cathaysian cordaitaleans from non-peat-forming environments are poorly known. Cordaitaleans, as close relatives of modern conifers, had a long geological history in the Cathaysia from the Visean (Mississippian, lower Carboniferous) to the end of Permian. They became prominent since the late Pennsylvanian, and best developed during the Cisuralian (early Permian) in North China, serving as the volumetrically dominant to subdominant elements of wetland floras. Architecture and ecology of the Cathaysian cordaitaleans from non-peat-forming environments are poorly known. Dr. WANG Mingli and other researchers from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), recently found 211 giant cordaitalean trunks and described their morphology and brief anatomical features from the Cisuralian Taiyuan Formation in Yangquan, Shanxi Province, North China. This results have been published online in Palaeoworld. It is reported that the discovery of the giant cordaitalean trunks has attracted great attention from the local government, and has been listed as a key protection object by the Yangquan City Planning and Natural Resources Bureau. It is planned to build a fossil remains park and museum on this basis. These trunks are characterized by the Artisia-like pith and pycnoxylic xylem. Absence of growth rings in the logs suggests they grew under non-seasonal humid tropical conditions. They are preserved in sandstone bodies interpreted as deposits of distributary river channels on the delta plain. Several trunks with attached rooting systems indicate that these trees may have been growing on channel levees or delta plains and brought into the channels by lateral bank erosion. Allometric estimates of tree height suggests that the largest trees were up to approximately 43.5 m tall. Mature cordaitaleans with straight trunks were probably the tallest trees and formed the canopy of the riparian forest in North China during the Cisuralian. This study was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, the National Natural Science Foundation of China, Youth Innovation Promotion Association CAS and the National Science Foundation. Reference: Wan, M.L., Yang, W., Wan, S., Li, D.D., Zhou, W.M., He, X.Z., Wang, J., 2020. Giant cordaitalean trees in early Permian riparian canopies in North China: Evidence from anatomically preserved trunks in Yangquan, Shanxi Province. Palaeoworld, https://doi.org/10.1016/j.palwor.2020.04.008
Chrono- and lithostratigraphy of the Taiyuan Formation in Yangquan, Qinshui Basin, Shanxi Province, North China(A), in addition to the gross morphology (B-D) and anatomical features (E-H) of the trunks.
Reefs are important marine ecosystems in marine, and an excellent tool for tracking marine ecosystem changes, especially through mass extinction transitions. During the geological history, the earliest marine reef ecosystems were formed of stromatolites and flourished during the Precambrian before declining in the Phanerozoic. Metazoan reefs first appeared in the late Ediacaran and proliferated during the Phanerozoic, albeit with time gaps after mass extinction events, which are often marked by microbial reef proliferation. During the Middle-Late Devonian, the largest area of metazoan (stromatoporoid-coral) reefs of the Phanerozoic occurred, which covered about five million square kilometres (10 times the surface area of modern reef ecosystems). The Late Devonian Frasnian-Famennian (F-F) Kellwasser and the end-Devonian Hangenberg extinctions caused the collapse and disappearance of stromatoporoid-coral ecosystems, respectively. The succeeding Mississippian has long been assumed to be an interval dominated by microbial reefs, and lack of metazoan reefs. Small-sized metazoan reefs gradually reappeared during the middle-late Mississippian (Visean Stage). However, due to low-resolution and limited data available in previous studies, the timing and style of metazoan reef recovery in the Mississippian are unclear. Recently, Dr. YAO Le from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Dr. Markus Aretz from the University of Toulouse 3, and Prof. Paul, B. Wignall from the University of Leeds, systematically reviewed and documented the reef composition, distribution and evolutionary process from the Late Devonian to Mississippian, and uncovered the re-emergence of the Mississippian coral reef ecosystems after the Late Devonian mass extinctions. Relevant findings were published online on 16th December, 2019 in Earth-Science Reviews. Previous reports of the late Visean coral bioconstructions from the Western Europe and North Africa (western Palaeotethys Ocean), may mark the first metazoan reef proliferation after the Hangenberg extinction. In this study, abundant coral reefs, coral frameworks and coral biostromes were described from the late Visean strata on the South China Block (eastern Palaeotethys Ocean). The occurrence of these coral bioconstructions further suggests that the late Visean coral reef recovery may have been a widespread phenomenon. Based on the high-resolution reef database constructed in this study, three sub-intervals of the Mississippian metazoan reef recovery were distinguished, which are (1) metazoan “reef gap” phase (MRG) without metazoan reefs during the Tournaisian; (2) metazoan reef re-establishment phase (MRR) containing a few metazoan reefs from early Visean to early part of the late Visean; and (3) metazoan reef proliferation phase (MRP) with global coral reef flourishment during the middle part of the late Visean (late Asbian to early Brigantian substages). Coral reef proliferation at this time showed that the Mississippian was not solely a period dominated by microbial reefs. Late Visean coral reef development coincided with increased nektonic and benthic diversity, showing that stable marine ecosystems developed during this time. Even compared with other slow reef-recovery intervals, such as the middle-late Cambrian and Early-Middle Triassic with the intervals until the MRR and MRP of 5 Ma and 2 Ma, and 15 and 9 Ma respectively, the Mississippian metazoan reef recovery was the longest in reef history with about 12 Ma and 23 Ma until the MRR and MRP, respectively. Harsh climatic and oceanic conditions were present during the Mississippian, mainly including the widespread marine anoxia during the middle part of Tournaisian and the following recurrent glacial and interglacial climatic episodes with frequent changes in sea level, sedimentary facies and sea-water surface temperature, which may have stymied metazoan reef recovery during this time. During the late Visean, marine communities flourished during a phase of relative warm conditions and high sea level, and coincided with the long-delayed re-emergence of coral reef ecosystems after the Late Devonian extinctions. This research was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Natural Science Foundation of Jiangsu Province. Article information：Yao, L*., Aretz, M., Wignall, P.B., Chen, J.T., Vachard, D., Qi, Y.P., Shen S.Z., Wang, X.D., 2019. The longest delay: Re-emergence of coral reef ecosystems after the Late Devonian extinctions. Earth-Science Reviews. DOI: https://doi.org/10.1016/j.earscirev.2019.103060. Composition and evolutionary pattern of the Late Devonian to Mississippian reefs, and their relations to coeval changes in reef builders and palaeoenvironments Field (A-E), polished-slab (F-G) and thin-section photographs of the late Visean (Mississippian) coral reefs in South China
Field photographs of the late Visean coral reefs from other areas, e.g., Morocco (A), England (B-D), Australia (E) and Japan (F)
Taxaceae, commonly known as yews, is widely cultivated all over the world and has been loved by most people. Taxaceae sensu stricto includes Taxus (yew), Pseudotaxus (whiteberry yew), Amentotaxus (catkin-yew), Austrotaxus (New Caledonia yew), and Torreya. Many species of yews are endangered in the wild. Extant Amentotaxus comprises five to six species, which all are the endangered species on the IUCN list. The Taxaceae has a long history as the earliest group in the fossil record appeared in the earliest Jurassic, and probably had a certain diversity during the Jurassic and the Cretaceous. However, well-preserved fossil yews carrying important information have been extremely limited, especially absence of fossils preserved with reproductive organs, which result in the insufficient of our understanding of the origin and early evolution of the Taxaceae. Recently, Dr. DONG Chong, Dr. SHI Gongle, and Professor WANG Yongdong of the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Science (NIGPAS), and other members from the Chicago Botanic Garden, the Oak Spring Gardens Foundation and School of Forestry and Environmental Studies, Yale University, collaborated with a research focusing on the Middle？Late Jurassic yew fossils from the Daohugou Biota in northeastern China. Comparative morphological evidence and morphological phylogenic analysis both support that the fossils can be assigned to the genus Amentotaxus. The results show that, like Ginkgo, the catkin-yew is another living fossil dating back to the Middle？Late Jurassic that have undergone little morphological change over at least ~ 160 million years. This study was published online on June 2020 in the National Science Review, a high-level comprehensive academic journal. The fossils were collected from the Daohugou Bed in the Daohugou village in Ningcheng County, Inner Mongolia. Well-preserved catkin-yew fossil shoots have linear-lanceolate leaves borne in opposite pairs that are decussately inserted, and opposite ultimate shoots that spread in more or less a single plane. Attached seed-bearing structures arise singly from the axil of a normal vegetative leaf and consist of a short, naked axis bearing a single terminal seed that is enclosed by up to five pairs of opposite and decussate bracts. These features closely resemble those of the extant catkin-yew Amentotauxs. A close relationship of the Daohugou fossils to extant catkin-yews is consistent with the results of a phylogenetic analysis based on 13 groups scored for three Jurassic Taxaceae fossil species, and six extant species representing Cephalotaxus and the five genera Taxaceae. Both an unconstrained analysis and an analysis with the relationships of extant Taxaceae constrained to the topology of the molecular phylogeny support that it would be reasonable to assign to the Daohugou fossils to the catkin-yew Amentotauxs. The Middle？Late Jurassic Daohugou fossils confirm that the origin of the catkin-yew was at least 160 million years ago. “Living fossil” firstly appeared in Darwin’s book on the Origin of Species in 1859. The morphological stasis reflected by the “Living fossil” is one of the most interesting scientific topics in evolutionary biology. China is rich in plant diversity, including a large number of ancient families or genera and relict groups. The credible fossil record of relictual genera such as Craigia, Davidia, Cyclocarya and Metasequoia extend back to the early Cenozoic, and Taiwania and Hedyosmum extend back into the Cretaceous. However, the extent of morphological stasis between Daohugou fossils and extant Amentotaxus highlights that, like Ginkgo, Amentotaxus is a living fossil and its earliest record extends back into the Jurassic. This research was jointly supported by the National Science Foundation of China, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, the U. S. National Science Foundation, and Youth Innovation Promotion Association, CAS. Article reference: Dong Chong, Shi Gongle*, Herrera F., Wang Yongdong, Herendeen P. S., Crane P. R., Middle-Late Jurassic fossils from northeastern China reveal morphological stasis in the catkin-yew. National Science Review. https://doi.org/10.1093/nsr/nwaa138 (a, b) cf. Amentotaxus from the Middle-Late Jurassic Daohugou Bed in eastern Inner Mongolia; (c, d) Extant Amentotaxus; (e, f) Reconstructive drawings of the cf. Amentotaxus from the Daohugou biota.
Nature is full of colors, from the radiant shine of a peacock’s feathers or the bright warning coloration of toxic frogs to the pearl-white camouflage of polar bears. Nature is full of colors, from the radiant shine of a peacock’s feathers or the bright warning coloration of toxic frogs to the pearl-white camouflage of polar bears. Usually, fine structural detail necessary for the conservation of color is rarely preserved in the fossil record, making most reconstructions of the fossil based on artists’ imagination. A research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) has now unlocked the secrets of true coloration in the 99-million-year-old insects. Colors offer many clues about the behaviour and ecology of animals. They function to keep organisms safe from predators, at the right temperature, or attractive to potential mates. Understanding the coloration of long-extinct animals can help us shed light on ecosystems in the deep geological past. The study, published in Proceedings of the Royal Society B on July 1, offers a new perspective on the often overlooked, but by no means dull, lives of insects that co-existed alongside dinosaurs in Cretaceous rainforests. Researchers gathered a treasure trove of 35 amber pieces with exquisitely preserved insects from an amber mine in northern Myanmar. “The amber is mid-Cretaceous, approximately 99 million years old, dating back to the golden age of dinosaurs. It is essentially resin produced by ancient coniferous trees that grew in a tropical rainforest environment. Animals and plants trapped in the thick resin got preserved, some with life-like fidelity,” said Dr. CAI Chenyang, associate professor at NIGPAS who lead the study. The rare set of amber fossils includes cuckoo wasps with metallic bluish-green, yellowish-green, purplish-blue or green colors on the head, thorax, abdomen, and legs. In terms of color, they are almost the same as cuckoo wasps that live today, said Dr. CAI. The researchers also discovered blue and purple beetle specimens and a metallic dark-green soldier fly. “We have seen thousands of amber fossils but the preservation of color in these specimens is extraordinary,” said Prof. HUANG Diying from NIGPAS, a co-author of the study. “The type of color preserved in the amber fossils is called structural color. It is caused by microscopic structure of the animal’s surface. The surface nanostructure scatters light of specific wavelengths and produces very intense colors. This mechanism is responsible for many of the colors we know from our everyday lives,” explained Prof. PAN Yanhong from NIGPAS, a specialist on palaeocolor reconstruction. To understand how and why color is preserved in some amber fossils but not in others, and whether the colors seen in fossils are the same as the ones insects paraded more than 99 million years ago, the researchers used a diamond knife blades to cut through the exoskeleton of two of the colorful amber wasps and a sample of normal dull cuticle. Using electron microscopy, they were able to show that colorful amber fossils have a well-preserved exoskeleton nanostructure that scatters light. The unaltered nanostructure of colored insects suggested that the colors preserved in amber may be the same as the ones displayed by them in the Cretaceous. But in fossils that do not preserve color, the cuticular structures are badly damaged, explaining their brown-black appearance. What kind of information can we learn about the lives of ancient insects from their color? Extant cuckoo wasps are, as their name suggests, parasites that lay their eggs into the nests of unrelated bees and wasps. Structural coloration has been shown to serve as camouflage in insects, and so it is probable that the color of Cretaceous cuckoo wasps represented an adaptation to avoid detection. “At the moment we also cannot rule out the possibility that the colors played other roles besides camouflage, such as thermoregulation,” adds Dr. CAI. This research was supported by the National Natural Science Foundation of China, Chinese Academy of Sciences, and the Youth Innovation Promotion Association, CAS. Reference: Cai C*, Tihelka E, Pan Y*, Yin Z, Jiang R, Xia F, Huang D. (2020) Structural colours in diverse Mesozoic insects. Proc. R. Soc. B 287: 20200301. doi:10.1098/rspb.2020.0301 Fig. 1. Diverse structural-colored insects in mid-Cretaceous amber from northern Myanmar (Image by NIGPAS) Fig. 2. Comparisons between original and altered metallic colors in cleptine wasps (Image by NIGPAS)
Macroalgae, which are usually multicellular or coenocytic eukaryotes, play an important role, both ecologically and biogeochemically, in modern marine ecosystems. Molecular clock studies suggest that eukaryotic algae have an evolutionary deep history tracing back to the Paleoproterozoic to Mesoproterozoic. However, fossil biomarkers indicate that prokaryotes were the only notable primary producers in pre-Cryogenian oceans and it was not until the Cryogenian that eukaryotic algae rose to ecological prominence. The fossil record of macroalgae during the Tonian Period is poorly documented, hampering our ability to evaluate the potential ecological and geobiological importance of early macroalgae. Moreover, compared with Ediacaran macroalga assemblages, the taxonomic diversities of Tonian macroalga assemblages are usually considered much lower and their morphology relatively simple. Macroalgae, which are usually multicellular or coenocytic eukaryotes, play an important role, both ecologically and biogeochemically, in modern marine ecosystems. Molecular clock studies suggest that eukaryotic algae have an evolutionary deep history tracing back to the Paleoproterozoic to Mesoproterozoic. However, fossil biomarkers indicate that prokaryotes were the only notable primary producers in pre-Cryogenian oceans and it was not until the Cryogenian that eukaryotic algae rose to ecological prominence. The fossil record of macroalgae during the Tonian Period is poorly documented, hampering our ability to evaluate the potential ecological and geobiological importance of early macroalgae. Moreover, compared with Ediacaran macroalga assemblages, the taxonomic diversities of Tonian macroalga assemblages are usually considered much lower and their morphology relatively simple. A team of scientists led by Dr. PANG Ke from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and Drs. LI Guangjin and CHEN Lei from Shandong University of Science and Technology collected thousands of specimens from a fossiliferous horizon in the ca.~910 Ma to ~720 Myr rocks (Shiwangzhuang Formation, Tumen Group) from western Shandong Province, North China. Related results have recently been published in the Precambrian Research. The Shiwangzhuang assemblage consists of macroscopic and diversified carbonaceous compression fossils. In total, the Shiwangzhuang assemblage consists of twelve genera, sixteen species and one type of unnamed filaments, including a new genus and six new species: Anqiutrichoides constrictus n. gen. and sp.; Eosolena magna n. sp.; Protoarenicola baishicunensis n. sp.; Protoarenicola shijiacunensis n. sp.; Pararenicola gejiazhuangensis n. sp.; Sinosabellidites huangshanensis n. sp. The taxonomic diversity of the Shiwangzhuang assemblageis remarkable. It is more diverse than many other Tonian macrofossil assemblages all over the world. Indeed, the Shiwangzhuang assemblage nearly matches the Ediacaran Lantian and Miaohe biotas in terms of taxonomic diversity. Eleven taxa of the Shiwangzhuang assemblage are likely eukaryotic organisms on the basis of morphological features and sub-millimetric to millimetric size, whereas four taxa of the Shiwangzhuang assemblage are likely of cyanobacterial origin and two taxa are left undetermined in terms of biological affinity. Three taxa, including Anqiutrichoides constrictus, Eosolena magna, and Chuaria colony, show evidence of simple multicellularity with delicately preserved cellular structure. Among them, Anqiutrichoides constrictus and Eosolena magna consist of submillimetric to millimetric giant cells and comparable to giant-celled green algae. Seven tubulartaxa, including Protoarenicola baiguashanensis, Protoarenicola baishicunensis, Protoarenicola shijiacunensis, Pararenicola huaiyuanensis, Pararenicola gejiazhuangensis, Sinosabellidites huainanensis, and Sinosabellidites huangshanensis, are likely coenocyticalgae with diagnostic transverse annulations. Among them, Protoarenicolais characterized byannulated tubes with a bulbous terminal structure at one end, Pararenicola is characterized by annulated tubes with a constricted opening at one end and a round and closed termination at the other end, and Sinosabellidites is characterized by annulated tubes with two round and closed ends. The new Shiwangzhuang assemblage provides an important window onto the evolution of pre-Cryogenian macroalgae. It indicates that some eukaryotic clades had achieved macroscopic growth through simple multicellularity or coenocytism, paving the way, either ecologically or phylogenetically, for the eventual appearance of complex multicellularity. The abundant occurrence of diverse macroalgae in the Shiwangzhuang Formation also implies that the Tonian diversity of multicellular or coenocytic macroalgae is probably underestimated and macroscopic photoautotrophs may have played important roles, both ecologically and geobiologically, at least at a local scale in the Tonian. In addition, there are some biostratigraphically significant genera, including the Chuaria-Tawuia and Sinosabellidites-Protoarenicola-Pararenicola assemblages, indicating a Tonian age for the Shiwangzhuang Formation. This research was supported by the National Key Research and Development Program of China, National Natural Science Foundation of China, Chinese Academy of Sciences, Shandong University of Science and Technology Research Fund, Taishan Scholars Project, and State Key Laboratory of Palaeobiology and Stratigraphy. Reference: Li, G#., Chen, L.#*, Pang, K.*, Zhou, G., Han, C., Yang, L., Lv, W., Wu, C., Wang, W., Yang, F. An assemblage of macroscopic and diversified carbonaceous compression fossils from the Tonian Shiwangzhuang Formation in western Shandong, North China. Precambrian Research,2020, 346: 105801. Fig.1 Chuariacircularis and Chuaria colonies (A-C), Tawuia dalensis (E-G), Vendotaenia sp. (H-I), Mucoplagum primitivum (J), Glomulus filamentum (K), Unnamed filaments (L) and Beltina danai (M) from the Shiwangzhuang assemblage Fig.2. Protoarenicola baiguashanensis (A-B), Protoarenicola baishicunensis n. sp. (C-E), Protoarenicola shijiacunensis n. sp. (F-G), Pararenicola huaiyuanensis (H-I), Pararenicola gejiazhuangensis n. sp. (J–K), Sinosabellidites huainanensis (L), Sinosabellidites huangshanensis n. sp. (M) from the Shiwangzhuang assemblage Fig.3 Anqiutrichoides constrictus n. gen. and sp. (A-E) and Eosolena magna n. sp. (F-J) from the Shiwangzhuang assemblage
