Umenocoleidae is one of the most perplexing fossil insect groups. It was first established based on a specimen (Umenocoleus sinuatus Chen et T’an, 1973) from the Lower Cretaceous of Yumen City (Gansu Province, northwestern China). The systematic position of the genus has long been disputed, and it has variously been assigned to stem-group Coleoptera, Protelytroptera, Blattaria, stem-group Dictyoptera, or Mantodea, mainly because its sclerotized forewings and its forewing venation similar to stem-group Coleoptera, some groups of Dictyoptera, and Protelytroptera. Umenocoleidae is one of the most perplexing fossil insect groups. It was first established based on a specimen (Umenocoleus sinuatus Chen et T’an, 1973) from the Lower Cretaceous of Yumen City (Gansu Province, northwestern China). The systematic position of the genus has long been disputed, and it has variously been assigned to stem-group Coleoptera, Protelytroptera, Blattaria, stem-group Dictyoptera, or Mantodea, mainly because its sclerotized forewings and its forewing venation similar to stem-group Coleoptera, some groups of Dictyoptera, and Protelytroptera. Some researchers restricted Umenocoleidae to its type genus Umenocoleus and retransferred it to Coleoptera, proposing the placement of Umenocoleus as sister group to all other beetles, while the other genera remained in Dictyoptera. If it is true, the systematic position of Umenocoleidae will be very important for us to understand the origin and early evolution of Coleoptera. However, the placement of Umenocoleus is still under debate. Recently, Mr. LUO Cihang, a postgraduate student, supervised by Prof. WANG Bo and Prof. ZHANG Haichun come from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), studied new specimens from the type horizon of the type locality (Lower Cretaceous Zhonggou Formation at Jiuquan, Yumen City, China). The result indicates that the Umenocoleidae is likely a specialized taxon of Dictyoptera, sister to Alienoptera. The beetle-like appearance is a result of convergent evolution. This research was published on Palaeoworld. The research group described three new specimens from the type horizon of the type locality (Lower Cretaceous Zhonggou Formation of Yumen City, China), one of the type species, and two forewings of Ponopterix, a genus potentially closely related to Umenocoleus. They also re-examined the forewings of U. nervosus from the Lower Cretaceous Dalazi Formation, and two additional species (Enervipraeala nigra Luo, Xu et Jarzembowski, 2021, and another based on one undescribed specimen) preserved in mid-Cretaceous Kachin amber. The results revealed that though cup-shaped punctures on the forewings of Umenocoleidae are superficially similar to the window punctures of stem-group Coleoptera and extant Archostemata, their micro-structure are different. The researchers also carried out a phylogenetic analysis based on a matrix with 72 characters and 36 terminals, which provided robust evidence that the Umenocoleidae is a specialized taxon of Dictyoptera, sister to Alienoptera. Menocoleidae was a successful globally distributed family during the Early Cretaceous but had never been discovered from the Late Cretaceous, which probably accompanied by the decline of gymnosperms and in competition with wood-associated polyphagan beetles. Umenocoleidae (and also Alienopteridae) were apparently a failed attempt of roachoids to occupy a new microhabitat. This research was jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, and National Natural Science Foundation of China.Mr. Yan Fang and Ms. Chun-Zhao Wang of NIGPAS were acknowledged for their help with the SEM analysis. Reference:Luo, C.-H., Beutel, R.G., Thomson, U.R., Zheng, D.-R., Li, J.-H., Zhao, X.-Y., Zhang, H.-C., Wang, B., 2021. Beetle or roach: systematic position of the enigmatic Umenocoleidae based on new material from Zhonggou Formation in Jiuquan, Northwest China, and a morphocladistic analysis. Palaeoworld. https://doi.org/10.1016/j.palwor.2021.01.003 Fig. 1. Photographs and line drawings of Umenocoleidae Fig. 2. Systematic position and distribution of the Umenocoleidae Fig. 3. Ecological reconstruction of Umenocoleidae (drawing by Jahao Li) Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Although the Cretaceous is considered to have been a period with a warm-hot, greenhouse climate (Huber et al., 2002; O'Brien et al., 2017), Earth's climate during the Cretaceous underwent significant changes from a very warm mid-Cretaceous greenhouse climate to a long-term cooling period during the latest Cretaceous (Dhondt and Arthur, 1996; Linnert et al., 2018). Although the Cretaceous is considered to have been a period with a warm-hot, greenhouse climate (Huber et al., 2002; O'Brien et al., 2017), Earth's climate during the Cretaceous underwent significant changes from a very warm mid-Cretaceous greenhouse climate to a long-term cooling period during the latest Cretaceous (Dhondt and Arthur, 1996; Linnert et al., 2018). During the late Campanian–Maastrichtian, several major biotic events occurred, and a variable global greenhouse climate was established (Barrera, 1994; Macleod, 1994; Nordt et al., 2003; Wilf et al., 2003; Voigt et al., 2010; Jung et al., 2012). The Campanian–Maastrichtian Boundary Event (CMBE) represents a cooling phase registered in the δ18O values extracted from shells of planktonic and benthic foraminifera (Barrera, 1994). It was characterized by a negative δ13Ccarb excursion in bulk carbonates (Voigt et al., 2010), lasting ~1.6 Myr in the Campanian–Maastrichtian transition (ca. 72.1–70.5 Ma; Jung et al., 2012). The simultaneous biotic changes included the extinction of inoceramid bivalves at high latitudes (Johnson and Kauffman, 1990; Macleod and Huber, 1996), widespread changes of phytoplankton communities and expansion of cool water taxa (Linnert et al., 2016; Dameron et al., 2017), and the diversity of angiosperms declined abruptly in North American (Johnson, 1992). The Mid-Maastrichtian Event (MME) (ca. 69 Ma according to Frank et al., 2005) was first recognized because of the global extinction of inoceramid bivalves (MacLeod, 1994). The MME was marked by high atmospheric pCO2 on land (Wilf et al., 2003), an increase in ocean temperatures (Jung et al., 2013), and a positive carbon isotope excursion (Voigt et al., 2012). This warming trend has been found in the western Central Pacific (Jung et al., 2013) and South Atlantic (Li and Keller, 1999). The biotic changes included an abrupt disappearance of rudist reefs (Johnson and Kauffman, 1990), the extinction of a long-ranging, widespread group of bottom-dwelling inoceramids at low latitudes (Macleod, 1994; Macleod and Huber, 1996; Bralower et al., 2002; Dameron et al., 2017), and an increase in the diversity and abundance of ammonites in Antarctica (Witts et al., 2015). The latest Maastrichtian warming event (which took place during the last 450–110 kyr before the K/Pg boundary, Cretaceous/Paleogene boundary, according to Li and Keller, 1999) has been detected in marine and terrestrial systems, based on studies of oxygen isotopes of foraminifera in the South Atlantic (Li and Keller, 1999), leaf margin analysis used to estimate temperatures in North Dakota, USA (Wilf et al., 2003), and the estimation of atmospheric CO2 from pedogenic carbonate nodules in Texas, USA (Nordt et al., 2003). During this warming period, the planktonic foraminifera underwent a part of extinction, with the proliferation of opportunist disaster species and dwarfism (Abramovich and Keller, 2003; Abramovich et al., 2010), the major acme of the warm-water species of calcareous nannofossils were found in the Tropical Pacific, with a lowering of fertility levels and a drop of species richness (Thibault and Gardin, 2010), and the land plants in North Dakota became abundant and diversified (Wilf and Johnson, 2004). However, few studies have focused on the response of aquatic biotas to these significant global climate changes during the Late Cretaceous, and no terrestrial biotic response has previously been reported in the CMBE and MME due to the lack of continuous non-marine sequences rich in fossils. Dr. LI Sha, Prof. WANG Qifei and Prof. ZHANG Haichun, from the ‘Modern terrestrial ecosystem origin and early evolution’ at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), collaborated with Dr. Josep Sanjuan, from American University of Beirut-AUB, and Prof. WAN Xiaoqiao, from China University of Geosciences, Beijing, studied the response of the lacustrine flora in East Asia to global climate changes across the K/Pg boundary. This research was recently published on Global and Planetary Change. The global climate during the latest Cretaceous became variable, with several global warming and cooling trends in a context of a greenhouse Earth. The responses of marine ecosystems to these climate events are relatively well known worldwide; however, lacustrine responses are poorly known due to the less frequent and discontinuous terrestrial fossil records. The relative changes in charophyte diversity in continuous lacustrine sedimentary sequences from two basins in East Asia, i.e., Songliao and Jiaolai, are considered here for the first time to establish their correlation with global climate changes during the Late Cretaceous and K/Pg boundary, compared with the well-studied south European Ibero-Armorican Island. Lacustrine deposits correlated with the Campanian–Maastrichtian Boundary Event (CMBE), related to a long cooling period provided a relatively low diversity in East Asia. In contrast, we detected a diverse charophyte flora in lacustrine deposits correlated with the Mid-Maastrichtian Event (MME) in East Asia in a global warming trend. A higher charophyte diversity was further found in the End-Cretaceous global warming event due to speciation under the background of latest Maastrichtian warming event (LMWE). During the LMWE, Characeae species such as Microchara cristata reduced its size significantly due to environmental stress probably related to the Deccan volcanism. On the other hand, a general tendency of increasing the gyrogonite size in new Characeae taxa has been detected in populations extracted from lower Danian deposits, probably related to stable palaeoenvironmental conditions in a global cooling context. This study represents the first attempt to correlate the response of the charophyte flora to global climate changes in permanent lacustrine systems during the three main Late Cretaceous–early Danian climatic turnovers. This study was jointly funded by the National Natural Science Foundation of China, and Strategic Priority Pre-Research Program (B) of the Chinese Academy of Sciences. Reference: Li, S., Sanjuan, J., Wang, Q.F., Zhang, H.C., Wan, X.Q., 2021. Response of the lacustrine flora in East Asia to global climate changes across the K/Pg boundary. Global and Planetary Change, 197, 103400. https://doi.org/10.1016/j.gloplacha.2020.103400. Fig. 1. Stratigraphic log of the SK-1(N) borehole showing the position (modified after Li et al., 2019) and diversity of charophytes correlated with temperatures calculated based on paleosol carbonate clumped isotopes (Zhang et al., 2018), oxygen isotopes of benthic and planktonic foraminifera (Li and Keller, 1999), leaf-margin analysis (Wilf et al., 2003) and paleosol carbonate oxygen isotopes (Nordt et al., 2003). Abbreviations: CMBE, Campanian–Maastrichtian Boundary Event; MME: Mid-Maastrichtian Event; LMWE: latest Maastrichtian warming event. Fig. 2. Comprehensive terrestrial responses of the charophyte flora, the palynological flora, seed cones and the ostracod fauna to global climate events, such as speciation and the dwarfing effect, and size changes on a large time scale. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China <!--[if supportFields]> ADDIN EN.REFLIST <![endif]--><!--[if supportFields]><![endif]-->
The Permian–Triassic transition witnessed the largest mass extinction event in Earth’s history, multiple mechanisms have been proposed to explain the cause of this catastrophe, however, relatively less attention has been paid to the paleogeography and major element chemistry of seawater and its possible link to mass extinction during this interval. Syndepositional massive marine dolostones could record the Mg isotope signature of contemporaneous seawater that hold clues of ancient Mg cycling. The Permian–Triassic transition witnessed the largest mass extinction event in Earth’s history, multiple mechanisms have been proposed to explain the cause of this catastrophe, however, relatively less attention has been paid to the paleogeography and major element chemistry of seawater and its possible link to mass extinction during this interval. Syndepositional massive marine dolostones could record the Mg isotope signature of contemporaneous seawater that hold clues of ancient Mg cycling. Recently, an international research team from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Nanjing University and University of Innsbruck investigated Mg isotopes of dolomite from three widely spaced carbonate sections in the Paleotethys to trace oceanic Mg cycling during this critical period. The research results were published in the international journal Earth and Planetary Science Letters. They found remarkable variation of δ26Mgdolomite values around the End-Permian extinction interval and anti-correlated with global perturbations in δ13Ccarbonate recorded from different localities in the Paleotethys. Generally, the dolomite δ26Mg values displayed a first-order increase from -2.1±0.1‰ at the end Permian to -1.6±0.2‰ in the early Triassic. Based on the high-precision temporal model, our results suggest that the δ26Mg of seawater fluctuated by 0.4‰ within ~750 kyr across the Permian–Triassic transition. Modeling reveals that the high rate of change in δ26Mgseawater is attributed to dramatically intensified dolomitization in a restricted oceanic environment. The restriction could have occurred to local basins that were separated from each other, however, our data are also consistent with a hypothesis of the Paleotethys Ocean being episodically separated from the Panthalassa Ocean around the Permian-Triassic transition. The restriction events within the Paleotethys Ocean could have significantly weakened the ocean’s buffering capacity against external disturbances, and exacerbated marine environmental crisis to the marine ecosystem. This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences, the National Natural Science Foundation of China and the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences. Reference: Hu, Z., Li, W.*, Zhang, H.*, Krainer, K., Zheng, Q.-f., Xia, Z., Hu, W., Shen, S.-z., 2021. Mg isotope evidence for restriction events within the Paleotethys ocean around the Permian-Triassic transition. Earth and Planetary Science Letters 556, 116704. DOI: 10.1016/j.epsl.2020.116704. Fig1. Global paleogeography at ～252 Ma and the location of studied sections, Lithological and C-Mg isotopic variations of carbonates along the studied sections in Paleotethys. Fig2. A comparison dolomite δ26Mg from end Permian to early Triassic for the western and eastern Paleotethys. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Previous studies have shown that the eukaryotic radiation continued from the Ediacaran Period to the Cambrian explosion, with when and how the earliest Ediacaran acanthomorphs occurred and diversified remaining not fully discussed, hampering our understanding to the initiation of the first global radiation of eukaryotes in Earth history. After more than one billion years of evolution and extreme conditions of the Neoproterozoic global glaciations, eukaryotic life began to thrive and diversify globally in the Ediacaran Period. This event initiated from the wide occurrence and diversification of the Ediacaran acanthomorphic acritarchs and multicellular algae. Previous studies have shown that the eukaryotic radiation continued from the Ediacaran Period to the Cambrian explosion, with when and how the earliest Ediacaran acanthomorphs occurred and diversified remaining not fully discussed, hampering our understanding to the initiation of the first global radiation of eukaryotes in Earth history. To resolve those problems, researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(NIGPAS), collaborating with researchers from the Virginia Tech., USA, have been working on the fossiliferous Ediacaran Doushantuo Formation in South China for decades, and one of their studies was published recently on Precambrian Research. Based on 1547 acanthomorphic acritarch specimens from the Doushantuo Formation at 3 sections, this work identified 24 genera and 69 species, including two new genera, six new species, five unnamed species, and three possible new forms tentatively placed in open nomenclatures, and discussed the temporal and spatial distribution of acanthomorphic acritarchs of the Doushantuo Formation, as well as implications for Ediacaran biostratigraphy. This paper reported acanthomorphs from the lowest chert nodule horizon of the Doushantuo Formation, with considerably high diversity, indicating a possible earlier appearance of these eukaryotic organisms, which has not been captured in the fossil record due to the lack of proper taphonomic conditions below this horizon. This finding also indicates that the First Appearance Data (FAD) of any acanthomorphic acritarch from this lowest chert nodule horizon in basal Member II may not serve as a good criterion for the base of the Second Ediacaran Stage (SES), thus other geological records are needed in searching for the basal boundary of SES. Upsection, altogether 21 species occurred within the 20 m strata above the cap dolostone, exceeding half of the total number of species (65.6%) from Member II of the Doushantuo Formation at Jiulongwan. Based on published cyclostratigraphic data, these results show that Ediacaran acanthomorphs diversified rapidly, reaching a considerably high diversity within about 10 Myrs after the end of Marinoan glaciation. In addition, combined with published acritarch data, this study discussed problems relating with biostratigraphic data from "composite sections", which had been widely used in previous studies, and proposed some regionally traceable taxa for future biostratigraphic studies of the Doushantuo Formation. This study was supported by the National Key R & D Program of China, National Natural Science Foundation of China, the Strategic Priority Research Program (B) of Chinese Academy of Sciences, and the U. S. National Science Foundation. Reference: Ouyang, Q., Zhou, C., Xiao, S., Guan, C., Chen, Z., Yuan, X., Sun, Y., 2021. Distribution of Ediacaran acanthomorphic acritarchs in the lower Doushantuo Formation of the Yangtze Gorges area, South China: Evolutionary and stratigraphic implications. Precambrian Research 353, 106005. https://doi.org/10.1016/j.precamres.2020.106005.
Newly erected genus and species Crassimembrana crispans gen. et sp. nov. and a new form Crassimembrana cf. C. crispans
Emended species Weissiella brevis emend. in this study
First appearance data (FADs) of some regionally traceable acanthomorph taxa in Member II from the Yangtze Gorges area
The surface and deep waters of the Philippine Sea flow into the South China Sea(SCS), and the Intermediate Water of the SCS into the Philippine Sea through the Luzon Strait, which shows a vertical "sandwich" structure from the surface to the bottom in the northeastern SCS. The studies about Benthic foraminferal and ostracodal have disclosed the late Pleistocene evolution of the deep water mass and ventilation in the SCS, which have provided important information of the paleo-environment. However, on the long-term scale, few dada was acquired from the SCS deep-water, especially for the water mass history before the final formation of the modern tectonic structure during the Miocene. During International Ocean Discovery Program (IODP) Expedition 367/368 in the northern SCS, the remarkable rhythmic reddish-brown and greenish-gray sediments were found during the Middle-Late Micoene, which provide valuable material to study the deep water property and its exchange with those of the Pacific Ocean. Professor LI Baohua from Nanjing institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Dr. JIN Xiaobo, Professor LIU Chuanlian and others from Tongji University conducted experiments on the 442-497m sediment at site U1502 (water depth 3764m) through dealing with the sediment color reflectance, nannofossil composition, key element content, and clay minerals to determine the origin of these cyclicity-like color transitions during the late Miocene. The above result was recently published in Marine Geology: It is inferred that the in-situ formed amorphous hematite caused the coloration of the reddish sediments, in which ferrum and manganese contents were high and carbonate was not poorly preserved. Therefore, the occurrence of the cyclicity-like color transitions reflects the extent of deep-water ventilation in the abyssal SCS. Such changes in deep-water ventilation were possibly related to an orbital-forced rearrangement of deep oceanic circulation in the Pacific Ocean. A well-ventilated bottom water and less- preserved carbonate in these reddish sediments was proposed to be contributed by the stronger mixing of the northern- and southern-sourced deep-water during the interglacial period. While, during the glacial period, when the Antarctic ice sheet expanded, the formation of the Antarctic deep-water was enhanced and resulted in a more isolated and intensified deep stratification of the abyssal water masses in the SCS, forming the green colored sediments. This study also provides important informations on the formation, evolution and environmental influence of the SCS. This study was supported by the National Natural Science Foundation of China, the National Science and Technology Major Project of the Ministry of Science and Technology of China, and the Strategic Priority Research Program of the Chinese Academy of Sciences. Reference: Jin, Xiaobo, Xu, Juan, Li, Yanli, Qiao, Peijun, Wu, Li, Ling, Cheng, Li, Baohua*, Liu, Chuanlian*, 2020. Origin of the rhythmic reddish-brown and greenish-gray sediments in the abyssal South China Sea: Implications for oceanic circulation in the late Miocene. 430: 106378. https://doi.org/10.1016/j.margeo.2020.106378. Manganese and ferrum contents, magnetic susceptibility and sediment color reflectance a* at Site U1502A Schematic deep-water ventilation in the (SCS) and the Pacific deep oceanic circulation during the glacial/interglacial cycles
The opening of Drake and Tasmania passages, the closures of the Central American isthmus and Indonesia sea way, and shutdown and reopening of the Gibraltar Straight played important role on the global ocean circulation and further influence the climate system and environment. After the Strait of Gibraltar re-opened at 5.33 million years ago, warm high-salinity Mediterranean outflow water (MOW) showered into the Gulf of Cadiz, north Atlantic, penetrating north along the Portuguese slope, even to the Norwegian- Greenland Sea region, which enhances the North Atlantic deep-water density and helps drive Atlantic Meridional Overturning Circulation (AMOC). The opening of Drake and Tasmania passages, the closures of the Central American isthmus and Indonesia sea way, and shutdown and reopening of the Gibraltar Straight played important role on the global ocean circulation and further influence the climate system and environment. After the Strait of Gibraltar re-opened at 5.33 million years ago, warm high-salinity Mediterranean outflow water (MOW) showered into the Gulf of Cadiz, north Atlantic, penetrating north along the Portuguese slope, even to the Norwegian- Greenland Sea region, which enhances the North Atlantic deep-water density and helps drive Atlantic Meridional Overturning Circulation (AMOC). Foraminiferal fauna contains the rich information of the surrounding water, and responses sensitively to the environmental changes. The benthic foraminifera has the priority on the bottom water reconstruction. In collaboration with scientists form Portugal and Korea, Dr. GUO Qimei of Professor LI BaohuaI’s research group at Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(NIGPAS) performed the paleoceanographic analyses on Integrated Ocean Drilling Program (IODP) Site U1391 off the Portuguese margin based on benthic foraminifera and stable Oxygen/ Carbon isotopes of their tests. The above result was recently published in Quaternary Science Reviews. The study reports the faunal composition and variation of benthic foraminifera during the last 1.3 Ma. Based on the high-resolution δ18O stratigraphy, “Elevated Epibenthos” group and Key species Planulina ariminensis contents of benthic foraminifera, the MOW dynamics across the middle Pleistocene transition (MPT) was reconstructed. The data suggests that the MOW intensity has typical glacial-interglacial cycles, an active MOW current during the interglacial periods and a sluggish MOW current during the glacial periods. The strength of MOW was enhanced during MISs 1, 9-11, 19-21, and 37-39, reaching the lately peak at MIS 11, when the sea level was considered to rise up to ~20 m above the present high-stand. The variation in the abundance of the “elevated epibenthos” group was dominated by ~41-kyr cycle prior to the MPT and by the ~100-kyr cycle after the MPT, which suggested there was an MPT-related shift in the MOW dynamics. The MOW variability of the last 1.3 Ma is the combination of the precession forcing and the obliquity forcing that work together. The precession forcing played an important role in the MOW dynamics of the entire time series, which explains the ~20-kyr high frequency oscillations in the “elevated epibenthos” record. The bottom water was well ventilated by MOW during the interglacial periods and by GNAIW during the glacial periods, and poorly ventilated during the glacial terminations. The study also delineates the partial evolution of Mediterranean outflow water after the reopening of the Gibraltar Straight. This work was supported by the Chinese Academy of Sciences (CAS) Strategic Priority Project, National Natural Science Foundation of China, the State Key Laboratory of Palaeobiology and Stratigraphy, and the Ministry of Ocean and Fisheries Korea (International Ocean Discovery Program) and IODP-China. Reference: Guo, Qimei*, Li, Baohua*, Voelker, Antje, Kim, Jin-Kyoung, 2020. Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin. Quaternary Science Reviews, 247: 106567. https://doi.org/10.1016/j.quascirev.2020.106567. Guo, Qimei, Li, Baohua*, Kim, Jin-Kyoung, IODP Expedition 339 Scientists, 2017. Benthic foraminiferal assemblages and bottom water evolution off the Portuguese margin since the Middle Pleistocene. Global and Planetary Change, 150: 94-108. http://dx.doi.org/10.1016/j.gloplacha.2016.11.004. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China General circulation pattern of the present Mediterranean Outflow Water (MOW) pathway in the eastern North Atlantic Scanning electron microscope pictures of the elevated epi-benthic foraminifera from Site U1391 Variation of the “Elevated Epibenthos” at Site U1391 during the last 1.3 Ma, its comparison with global oxygen stable isotope curve (LR04), local insolation and other paleoceanographic index
With a depositional history spanning the early Aptian to early Albian (~19 mys), the Lower Cretaceous Xinminpu Group in Jiuquan, NW China provides detailed record of an inland ecosystem responding to global climatic and environmental changes. The Xinminpu Group exhibits the most typical elements of the Jehol Biota found outside NE China, a highly diverse avifauna and a mid-Cretaceous angiosperm flora. The absence of a comprehensive stratigraphical framework for this area however limits the degree to which the unit can be interpreted relative to coeval sections and the geological records in genera. With a depositional history spanning the early Aptian to early Albian (~19 mys), the Lower Cretaceous Xinminpu Group in Jiuquan, NW China provides detailed record of an inland ecosystem responding to global climatic and environmental changes. The Xinminpu Group exhibits the most typical elements of the Jehol Biota found outside NE China, a highly diverse avifauna and a mid-Cretaceous angiosperm flora. The absence of a comprehensive stratigraphical framework for this area however limits the degree to which the unit can be interpreted relative to coeval sections and the geological records in genera. In the recent years, Dr. ZHENG Daran, Dr. LI Sha and Prof. ZHANG Haichun, from the research team of ‘Modern terrestrial ecosystem origin and early evolution’ of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), have carried out detailed geological investigations for the Lower Cretaceous in Jiuquan, NW China. About ten thousand fossils and rock samples were collected and analyzed for biostratigraphy, chronostratigraphy and geochemistry. A new comprehensive stratigraphical frame was provided for further discussing the inland biota evolution and environmental events. This research was recently published online in Earth-Science Reviews, and the main results of this research include: First, this framework suggests that the Chijinpu Formation correlates with the middle-upper Yixian and lower Jiufotang formations in western Liaoning, NE China and formed during the early Aptian (~124-120 Ma). The Xiagou Formation correlates with the upper Jiufotang and Shahai formations in western Liaoning and was deposited during the late early Aptian to earliest Albian (~120-112 Ma). The lowermost Zhonggou Formation was dated at 112.4 ± 0.3 Ma and thus may be contemporaneous with the Fuxin Formation in western Liaoning, which is of early-middle Albian age. Second, the typical Jehol Biota elements, namely the Eosestheria-Lycoptera-Ephemeropsis trisetalis assemblage, reached the Jiuquan area during the early Aptian and were preserved in the Chijinpu Formation. This early Aptian assemblage corresponds to the second and third evolutionary stages of the Jehol Biota. Third, a newly reported U-Pb age of 112.4 ± 0.3 Ma combined with previous Early Cretaceous volcanic ages for Jiuquan units demonstrate several periods of volcanic activity during OAE1a and OAE1b. The Hongliuxia craters were probably the eruption center for basalts emplaced around the Jiuquan and Changma basins. This more detailed chronostratigraphical framework will help strengthen correlations between inland and marine environments as recorded in sediments from this critical period of Earth history. Forth, the Ornithuromorpha-dominated avifauna from the Xiagou Formation of the Changma outcrop is similar to but more derived than the avifauna found in the Yixian and Jiufotang formations. The Changma avifauna appears just above OAE1a indicating that the early Aptian global climate change probably enhanced the evolution and diversification of early birds in this area. This study reviewed previous geological information in Jiuquan and combined it with new systematic palaeontological and isotopic data to provide a consistent biostratigraphical and chronostratigraphical interpretation. It laid foundation for the systematic study of the well-preserved Early Cretaceous ecosystem in Jiuquan, allowing us to understand correlations between inland and marine environments as recorded in sediments from this critical period. The research was supported by the Second Tibetan Plateau Scientific Expedition and Research, the General Research Fund of Hong Kong Research Grants Council, HKU Seed Fund for Basic Research, the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS). Reference: Zheng Daran*, Wang He, Li Sha*, Wang Bo, Jarzembowski E.A., Dong Chong, Fang Yanan, Teng Xiao, Yu Tingting, Yang Lichao, Li Yuling, Zhao Xiangdong, Xue Naihua, Chang Su-Chin*, Zhang Haichun * (2021). Synthesis of a chrono- and biostratigraphical framework for the Lower Cretaceous of Jiuquan, NW China: implications for major evolutionary events. Earth-Science Reviews, 213, 103474. https://doi.org/10.1016/j.earscirev.2020.103474. Figre1. Distribution and expansion of the Jehol Biota (map revised after Chen, 1999) Figure2. Biostratigraphy of the Lower Cretaceous Xinminpu Group of the Jiuquan Figure3. Early Cretaceous evolutionary and environmental events in Jiuquan
From their peculiarly flattened bodies to their odd siphonate mouthparts, fleas are some of the most bizarre insects alive. Yet the unusual anatomy that made the group successful parasites of birds and mammals has also puzzled generations of zoologists. Even despite sequencing the first flea genomes in the last decade, their early evolution and position on the insect tree of life has remained a mystery. Now, a new study by researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) in China and the University of Bristol in the UK promises to resolve this long-standing evolutionary riddle. With almost every aspect of their biology and anatomy adapted to their specialised parasitic lifestyle, the fleas have long troubled evolutionary biologists. From their peculiarly flattened bodies to their odd siphonate mouthparts, fleas are some of the most bizarre insects alive. Yet the unusual anatomy that made the group successful parasites of birds and mammals has also puzzled generations of zoologists. Even despite sequencing the first flea genomes in the last decade, their early evolution and position on the insect tree of life has remained a mystery. Now, a new study by researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) in China and the University of Bristol in the UK promises to resolve this long-standing evolutionary riddle. "Of all the parasites in the animal kingdom, fleas hold a pre-eminent position. After all, the Black Death, caused by a flea-transmitted bacterium, was the deadliest pandemic in the recorded history of mankind; it claimed the lives of possibly up to 200 million people in the 14th century. Yet despite their medical significance, the placement of fleas on the tree of life represents one of the most persistent enigmas in the evolution of insects," says Erik Tihelka, undergraduate at the University of Bristol who led the new study published in Palaeoentomology. Over the course of the years, researchers have proposed many hypotheses regarding the origin of fleas, most arguing that their closest relatives lie among the flies or scorpionflies, or both. Now, scientists used genome-scale sequences of fleas and all their possible close relatives, and analysed them using new statistical methods. By using more sophisticated algorithms to test all historically proposed hypotheses and search for new potential relationships, the team has come to an unexpected conclusion – fleas are a group of highly modified, parasitic scorpionflies. Scorpionflies are a group of small- to medium-sized flying insects distributed worldwide. About 600 species are currently known. The new study suggests that the small scorpionfly family Nannochoristidae endemic to the southern hemisphere whose adults probably feed on nectar is the closest relative of all living fleas. Despite looking very unlike the flea we know today, the Nannochoristidae in fact share surprising anatomical similarities with fleas such as characters of the head and the sperm pump. Why did the "flea mystery" remain so hard to resolve for so long? "A close relationship between Nannochoristidae and the fleas has been proposed in several past molecular analyses but was treated as likely an error. Ancient evolutionary radiations leave behind subtle clues in organisms’ genomes that can only be recovered with sophisticated models of molecular evolution. Moreover, the nannochoristids are a quite rare and little-studied group that only occurs in New Zealand, southeastern Australia, Tasmania, and Chile, so they are easy to overlook." explains Tihelka. "The new results suggest that we may need to revise our entomology textbooks. Fleas no longer deserve the status of a separate insect order, but should actually be classified within the scorpionflies," says Prof. CAI Chenyang, a professor from NIGPAS and expert on Mesozoic insects. The new findings agree with fossil evidence. "We have exceptionally preserved fossil fleas from the Jurassic and Cretaceous. In particular, some Jurassic fleas from China, about 165 million years old, are truly giant and measure up to two centimetres. They may have fed on dinosaurs, but that is exceedingly difficult to tell. What is more interesting is that these ancient fleas share important characters with modern scorpionflies," says CAI. "Sometime between the Permian and Jurassic, a group of scorpionflies started feeding on the blood of vertebrates. This group gave rise to the fleas as we know them today," adds Diying Huang, professor of invertebrate palaeontology at NIGPAS. "It is interesting.", comments Mattia Giacomelli, a PhD student at the University of Bristol who participated in the study. "We used to think that all blood-feeding parasitic insects basically started off by either being predators or living in close association with their vertebrate hosts, like in their nests. The case of fleas shows that blood feeding can evolve in groups that originally fed on nectar and other plant secretions. It seems that the elongate mouthparts that are specialized for nectar feeding from flowers can become co-opted during the course evolution to enable sucking blood." Reference: Erik Tihelka, Mattia Giacomelli, Diying Huang, Davide Pisani, Philip C. J. Donoghue, Chenyang Cai* (2020) Fleas are parasitic scorpionflies. Palaeoentomology 3(6): 641–653. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Marine red beds (MRBs) are considered as time-specific facies and have indicative significances in revealing the evolution of marine paleo-environments. In contrast to shallow-water and oceanic MRBs, deeper-water MRBs around deep subtidal zone received less attention. During the Floian to Darriwilian, a set of reddish limestones deposited along the marginal Yangtze Platform, South China, including the Zitai Formation as well as the middle parts of the Dawan and Meitan formations. Interestingly, the Early–Middle Ordovician is also the critical interval of the Great Ordovician Biodiversification Event (GOBE) in South China. Marine red beds (MRBs) are considered as time-specific facies and have indicative significances in revealing the evolution of marine paleo-environments. In contrast to shallow-water and oceanic MRBs, deeper-water MRBs around deep subtidal zone received less attention. During the Floian to Darriwilian, a set of reddish limestones deposited along the marginal Yangtze Platform, South China, including the Zitai Formation as well as the middle parts of the Dawan and Meitan formations. Interestingly, the Early–Middle Ordovician is also the critical interval of the Great Ordovician Biodiversification Event (GOBE) in South China. The Early-Paleozoic research team from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with specialists from Peking University and University of Science and Technology of China, has been carrying out the petrological, mineralogical and geochemical study on these MRBs, as exemplified by the Zitai Formation from Xiangshuidong section, Songzi County, Hubei Province and Daling section, Shitai County, Anhui Province. This progress has been accepted in the special issue VSI28 "Marine oxygenation, deoxygenation and life during the early Paleozoic" of Palaeogeography, Palaeoclimatology, Palaeoecology. Accordingly, significant increases were observed in the terrestrial elements (e.g., aluminum, iron) during the deposition of the MRBs instead of redox fluctuations, when the sedimentation rate has also increased. It suggests iron material of terrestrial origin rather than seawater oxygen level could be the most important factor for the MRBs. By providing nutrients into marine environment, increased terrigenous materials might facilitate the radiation of the planktonic acritarchs, chitinozoans and graptolites and benthic brachiopods during the Early-Middle Ordovician in South China, which means regionally environmental factors might be critical for biological radiations at the early stage of the GOBE. Reference: Luan, X.C., Zhang, X.L., Wu, R.C., Zhan, R.B., Liu, J.B., Wang, G.X., Zhang, Y.C., 2020. Environmental changes revealed by Lower–Middle Ordovician deeper-water marine red beds from the marginal Yangtze Platform, South China: Links to biodiversification. Palaeogeography, Palaeoclimatology, Palaeoecology. https://doi.org/10.1016/j.palaeo.2020.110116 (In press) Polished slabs of the Zitai MRBs Concentrations and influxes of aluminum and iron at the Xiangshuidong section Biodiversity curve, paleo-environmental conditions and distribution of marine red beds in South China during Ordovician
Fossils of about 15,000 bryozoan species have been found. Bryozoans are among the three dominant groups of Paleozoic fossils. The oldest species with a mineralized skeleton occurs in the Lower Ordovician. The Early Ordovician fossils may also represent forms that had already become significantly different from the original members of the phylum. In Silurian, bryozoans notably declined and were dominated by trepostome bryozoans. Bifoliate cryptostomes were also abundant and diverse in Silurian communities. Fossils of about 15,000 bryozoan species have been found. Bryozoans are among the three dominant groups of Paleozoic fossils. The oldest species with a mineralized skeleton occurs in the Lower Ordovician. The Early Ordovician fossils may also represent forms that had already become significantly different from the original members of the phylum. In Silurian, bryozoans notably declined and were dominated by trepostome bryozoans. Bifoliate cryptostomes were also abundant and diverse in Silurian communities. Cooperated with Dr. Andrej Ernst of the Hamburg University and Prof. Axel Munneck of the Erlangen University, Dr. LI Qijian from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) leaded and conducted a study on Bryozoans from the lower Silurian (Telychian) Hanchiatien Formation from southern Chongqing. Related results have been recently published online in the International Journal Journal of Paleontology. There are eight bryozoan species in those small reefs. Four species are new: the trepostomes Asperopora sinensis n. sp., Trematopora jiebeiensis n. sp., and Trematopora tenuis n. sp., and the fenestrate Moorephylloporina parvula n. sp. One species, the cystoporate Hennigopora sp. indet., is described in open nomenclature. The fenestrate bryozoans are eurytopic, occurring in all types of facies within the bioherms. Erect bryozoans formed pioneering communities on weakly cemented substrata, whereas encrusting fauna occurred on hardgrounds and formed densely compact framestones. Robust branched bryozoans tend to occur out of the reef core (Fig. 1) where they could have formed reef-flank thickets in more agitated conditions. The generic composition of the studied fauna correlates with other localities in South China, and they show general paleobiogeographic relations to Siberia and Indiana, USA (Fig. 2). This study was financially supported by the Youth Innovation Promotion Association, the National Natural Science Foundation of China, and the Chinese Academy of Science. This study is a contribution to the IGCP-653 ‘The onset of the Great Ordovician Biodiversity Event’ and the IGCP Project 668 ‘The stratigraphic and magmatic history of Early Palaeozoic equatorial Gondwana and its associated evolutionary Dynamics’. Reference: Ernst, A., Li, Q.J., Zhang, M., & Munnecke, A. (2020). Bryozoans from the lower Silurian (Telychian) Hanchiatien Formation from southern Chongqing, South China. Journal of Paleontology, 1-16. (DOI: https://doi.org/10.1017/jpa.2020.86). Fig 1．Field aspects of the studied section: (1) the flank facies of the second reef horizon, showing the branched bryozoan Trematopora; (2) the core facies of the second reef horizon; (3) plan view of the framestone, showing bulbous and knobby colonies of the first reef horizon; (4) the flank facies of the first reef horizon. Scale bars = 2 m (2); 8 cm (4); 2 cm (3); 1 cm (1).
Fig 2．Paleobiogeographical affinities of the studied bryozoan association and selected Telychian bryozoan faunas.
