Scientists have long been unclear as to when insect pollination first appeared. Now, an international research group from China and the U.S. has provided the earliest evidence of insect-angiosperm pollination – by analyzing a sample of Cretaceous Burmese amber. Results were published in Proceedings of the National Academy of Sciences (PNAS) on November 11. Most of our food is from angiosperms, while more than 90% of angiosperms require insect pollination – making this pollination method hugely important. Nevertheless, scientists have long been unclear as to when insect pollination first appeared. Now, however, an international research group from China and the U.S. has provided the earliest evidence of insect-angiosperm pollination – by analyzing a sample of Cretaceous Burmese amber. The research was led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology (NIGPAS) of the Chinese Academy of Sciences. Results were published in Proceedings of the National Academy of Sciences (PNAS) on November 11. Angiosperms, also known as flowering plants, originated in the Mesozoic and are the most diverse group of land plants, with approximately 300,000 known species. Their most distinguishing characteristic is the presence of true flowers. Angiosperms self-pollinate as well as use insects, animals, wind and water to achieve pollination, thus enhancing gene flow and increasing diversity. Angiosperms experienced rapid radiation by the mid-Cretaceous, which Darwin called an “abominable mystery.” Since Darwin’s time, numerous scholars have thought that insect pollination must be a key contributor to the Cretaceous radiation of angiosperms since insects and flowering plants were both common by this time. However, direct evidence of a Cretaceous insect-angiosperm pollination mode was missing and related theories remained hypothetical until now. Working with Burmese amber dating to the mid-Cretaceous – 99 million years ago – the researchers discovered evidence of beetle pollination, thus confirming the hypothesis of Cretaceous insect-angiosperm interaction and offering the earliest evidence for entomophily. The beetle specimen in the amber sample is a new species within the family Mordellidae, named Angimordella burmitina. Extant Mordellidae beetles are a typical flower-visiting group. Commonly, they are known as “tumbling flower beetles” for the irregular movements they make when escaping predators, due to having an elongated pygidium (an external posterior body part or shield in arthropods). A. burmitina is distinguished from most extant species by a poorly developed pygidium and enlarged, very well-developed hind legs. Based on these features, the scientists believe A. burmitina utilized a different movement mechanism than other species, preferring to jump or fly between corollas and plants. The mouth part of A. burmitina is also highly evolved for pollen collection, with enlargement of part of the maxillary palps, which are leg-like structures near the mouth. Numerous pollen grains were preserved on or near the A. burmitina specimen. To examine them closely, the research team performed high-precision grinding and polishing of the amber sample, then applied confocal laser scanning microscopy and optical photomicrography. Using these methods, the scientists identified the pollen grains as tricolpate, meaning they each have three pores and come from a type of flowering plant known as a eudicot. Their surface texture, size, and clumping also show that the pollen is zoophilous, making it more likely to be picked up by an animal such as a beetle. Based on the entomological and palynological evidence, the research team believes this amber specimen reveals a beetle-angiosperm pollination mode, supporting the hypothesis that specialized insect pollination modes were present in eudicots at least 99 million years ago. Previous evidence of insect pollination of flowering plants dates to the Middle Eocene, around 45-48 million years ago. Thus, the current finding extends the history of insect pollination of flowering plants by around 50 million years and suggests that such mutualism existed at least as far back as 99 million years ago. Reference: Bao Tong, Wang Bo, Li Jianguo, Dilcher D. (2019) Pollination of Cretaceous flowers. PNAS, doi:10.1073/pnas.1916186116.
Cretaceous tumbling flower beetle and tricolpate pollen grains.(Imaged by NIGPAS) Ecological reconstruction of the Cretaceous tumbling flower beetle.(Imaged by NIGPAS)
Chirality is present at all scales from molecule to galaxy, and plants are not exceptional. Plants with twisted axes are usually climbing “twiners”. In extant twiners, more than 90% of them prefer fixed right-handed helices. However, researchers reported in Current Biology that a Permian fern fossil possessed a fixed left-handed twining direction.
The origin of homochirality in nature was one of 125 great unanswered questions suggested by Science. Chirality is present at all scales from molecule to galaxy, and plants are not exceptional. Plants with twisted axes are usually climbing “twiners”. In extant twiners, more than 90% of them prefer fixed right-handed helices. However, researchers reported in Current Biology that a Permian fern fossil possessed a fixed left-handed twining direction. In geological history, the climbing habit may have already been present in the first Middle Devonian forests as indicated by possible climbers among aneurophytalean progymnosperms and lycopsids. By late Carboniferous climbing was more common and diverse as preserved in swamp forests with modes of attachment ranging from aerial roots to appendages modified into hooks and tendrils. However, direct preservation of a fossil twiner has only been documented in the Miocene Shanwang Formation of Eastern China (ca. 16 Ma), albeit with the identity of the twiner difficult to establish and likely to be a self-twiner. Recently, researchers form the Nanjing Institute of Geology and Palaeontology, CAS, China, the West Bohemian Museum in Pilsen, Czech Republic and the Stanford University, USA reported a new fossil twiner from the early Permian Wuda Tuff fossil Lagerst？tte of Inner Mongolia, China (ca. 298 Ma). The complete rotation confirms the twining habit dating back to the Paleozoic. The high fidelity of 3-D preservation allows the identification of the twiner and host plant. The twiner possesses a slightly C-shaped xylem strand anatomy without any secondary tissues and is thereby interpreted as a fern rachis. The associated plant fragments and attached pinnules from another twining specimen indicate the twiner to be an anachoropterid fern, which possesses a fixed left-handed twining direction. The host possesses a eustelic stem anatomy that generally indicates a seed plant affinity. It can be further classified as Callistophytales on account of additional material with the same stem anatomy and prickle structures collected from the same forest. Moreover, the host possesses heterophyllous pinnules on their fronds with some pinnules modified into pinnate linear lobes that terminate in swollen structures previously interpreted from similar material as adhesive pads, suggesting that the host plant is also a climber. The dual-climbing phenomenon is known from modern tropical and subtropical forests, but has never been documented in the fossil record. Although indirect evidence of the climbing habit was already common from the late Carboniferous tropical forest ecosystems, here direct preservation of the twining habit as well evidence of the dual-climbing phenomenon, indicating a high degree of ecological complexity in early Permian swamp forests. The study was supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences, the National Natural Science Foundation of China, the State Key Laboratory of Palaeobiology and Stratigraphy, and the Grant Agency of Czech Republic. Reference: Weiming Zhou, Dandan Li, Josef Psenicka, C. Kevin Boyce, Jun Wang*, 2019. A left-handed fern twiner in a Permian swamp forest. Current Biology. DOI:10.1016/j.cub.2019.10.005 Reconstruction of the dual-climbing phenomenon. (Imaged by NIGPAS)
The death march of a segmented bilaterian animal unearthed from ~550-million-year-old rocks in China shows that the oldest mobile and segmented animals evolved by the Ediacaran Period (635-539 million years ago). The research was published in Nature on Sept. 4 by an international research team from China and the U.S. Yilingia spiciformis body fossil (left), trace (right), and artist’s reconstruction (middle). (Image by NIGPAS) The death march of a segmented bilaterian animal unearthed from ~550-million-year-old rocks in China shows that the oldest mobile and segmented animals evolved by the Ediacaran Period (635-539 million years ago). The research was published in Nature on Sept. 4 by an international research team from China and the U.S. The origin of bilaterally symmetric animals (or bilaterians) with a segmented body plan is a monumental event in early animal evolution. Although scientists have estimated, on the basis of molecular clock analyses, that mobile and segmented bilaterians evolved in the Ediacaran Period, no convincing fossil evidence had been found to substantiate these estimates. Recently, however, an international research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and Virginia Tech in the United States reported the discovery of a segmented bilaterian fossil preserved in ~550-million-year-old rocks in China. What makes this fossil unusual is that it is directly connected with a trail it made. The new fossil indicates that mobile and segmented animals evolved by the terminal Ediacaran Period. It also helps scientists understand the producers of Ediacaran trace fossils, since such fossils are often not preserved with their trace makers. The new fossil species, found in the terminal Ediacaran Shibantan Formation of the Dengying Formation in the Yangtze Gorges area, is Yilingia spiciformis. It is an elongate and segmented bilaterian with repetitive and trilobate body units, which show anteroposterior and dorsoventral differentiation. One specimen is directly connected with the trace it produced immediately before death, thus allowing the authors to interpret other similar trace fossils that are preserved in the same unit but are not directly connected with the animals that produced them. The direct association with trace fossils suggests that Yilingia spiciformis was a mobile animal capable of locomotion. Evidence of body segmentation, polarity, and directional locomotion indicates that Yilingia spiciformis was a bilaterian animal. However, it is difficult to determine its exact phylogenetic position within the bilaterian family tree. The authors surmise that Yilingia spiciformis could be related to arthropods or annelids. As one of the few Ediacaran animals demonstrably capable of producing long and continuous trails, Yilingia spiciformis sheds new light on the origin of segmentation and its possible relationship with animal motility. The emergence of motile animals had a profound environmental and ecological impact on Earth surface systems and ultimately led to the Cambrian substrate and agronomic revolutions. The study was supported by the Chinese Academy of Sciences, the Ministry of Science and Technology of China, the National Natural Science Foundation of China, the U.S. National Science Foundation, and the National Geographic Society. Reference: Zhe Chen, Chuanming Zhou, Xunlai Yuan*, Shuhai Xiao*, 2019, Death march of a segmented and trilobate bilaterian elucidates early animal evolution. Nature, https://doi.org/10.1038/s41586-019-1522-7
Chitinozoans are organic-walled microfossils widely recorded in Ordovician to Devonian (about 400 million years ago) marine sediments and usually shaped like “bottles”, however, with a hitherto-unknown biologic affinity and used to be considered as metazoan eggs. Recently, researchers from China, Estonia and USA suggested that chitinozoans are more likely to be fossils of individual microorganisms rather than eggs. The results were published online on July 31, 2019 in Proceedings of the Royal Society B. Chitinozoans are organic-walled microfossils widely recorded in Ordovician to Devonian (about 400 million years ago) marine sediments and usually shaped like "bottles". Their biological affinity remains unknown, but most commonly, they are interpreted as eggs of marine metazoans. Recently, researchers from China, Estonia and USA suggested that chitinozoans are more likely to be fossils of individual microorganisms rather than eggs. The results were published online in Proceedings of the Royal Society B on July 31, 2019. Since their first description in the 1930s, multiple hypotheses have been put forward trying to explain their biological origin and ecology, including classification as protists, metazoans or egg capsules of metazoans. With the first report of some cocoon-like preservation in Desmochitina, chitinozoans have almost exclusively been interpreted as eggs of unknown marine metazoans, possibly some wormlike animals, during the last three decades. No further discussions related to their affinity have been advanced since then, even though the egg hypothesis makes no allowance for, nor does it explain, some of the morphological structures found in Chitinozoa. However, in a recent study conducted by Dr. LIANG Yan from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and her collaborators, the researchers re-evaluated the egg hypothesis from the perspective of morphological variation of chitinozoans. They conducted a detailed case study focusing on single highly variable species Hercochitina violana sp. nov. in order to allow for a more quantitative analysis. The scientists compiled a dataset of measurements of 378 randomly selected species representing all 57 chitinozoan genera currently known, as well as a dataset of coefficients of variation (CV) in eggs from 45 extant aquatic metazoan species. For the first time, this allowed a reliable comparison of the magnitude of size variation between chitinozoans and undisputed eggs to further assess their possible analogy. The results showed that the range of variation in most chitinozoans was much larger than that of eggs of extant marine invertebrates or the hitherto reported undisputed fossil eggs. The range and type of size variation shown in Hercochitina violana sp. nov. potentially indicated an ontogenetic series rather than an intraspecific variation. Additionally, there is no analogue in extant metazoan eggs which have such complicated and delicate structures as developed in chitinozoans, not to mention the rapid evolutionary trend of ornamentations, which is also inconsistent with the prevailing egg hypothesis. It is more plausible to argue that most chitinozoans, with the exception of the unique Desmochitina, represent independent organic-walled microorganisms rather than eggs of metazoans. Reference: Liang Y*, Bernardo J, Goldman D, Nolvak J, Tang P, Wang W, Hints O*. 2019 Morphological variation suggests that chitinozoans may be fossils of individual microorganisms rather than metazoan eggs. Proc. R. Soc. B 20191270.
SEM images of Hercochitina violana sp. nov. showing the morphologic variation. (Image by NIGPAS)
The climate on the earth has gradually warmed up since the last glacial maximum some 20,000 years ago. Appropriate climate conditions have contributed to the formation and development of the Holocene farming culture. The way of production and lifestyle for the ancient people gradually changed from the early collecting, fishing and hunting to the later settled production with farming agriculture. This change in production and lifestyle was closely related to the environment variations at that time, and had a great impact on the development of human civilization. Vegetation in southern China has undergone significant changes since the last glacial maximum. Given the limitations of data, we still lack a comprehensive understanding of the concrete changing process and its relationship with human farming life. In order to better understand the variations of vegetation with climate fluctuation since the last glacial maximum in southern China, as well as the impact of human activities on vegetation, a research team consisting of Prof. WANG Weiming, Dr. SHU Junwu and Dr. CHEN Wei from Nanjing Institute of Geology and Palaeontology of Chinese Academy of Sciences, and Dr. LI Chunhai from Nanjing Institute of Geography and Limnology of Chinese Academy of Sciences, has carried out pollen study for 20 drilling cores in some less researched areas. Finally, pollen data from 14 sites have been selected for the restoration of vegetation over the past 20,000 years. The research results have recently been published on the journal Chinese Science: Earth Sciences. The research team gave for the first time the vegetation zoning maps around 18 ka BP, 9 ka BP and 6 ka BP respectively, and the distribution characteristics of plants in each zone/subzone are described. The main results are as follows: 1) The variation of vegetation in southern China since about 20,000 years generally coincides with the changing process of global climate after the last glacial maximum. Temperate vegetation around 18 ka BP can extends southward to the present south subtropical subzone, reflecting that the nature of vegetation still retained some climatic characteristics of the previous glacial period, although the climate had begun to warm up at that time. 2) During the Holocene megathermal, the characteristics of vegetation in the study area are rather distinct, which indicates similar features around both 9 ka BP and 6 ka BP. This reflects the general trend of global warming at that time on the one hand, and the overall control of southeast monsoon and southwest monsoon in southern China on the other hand. It is speculated that the long-term strong monsoon climate since 9 ka may be the main reason for the dominant vegetation distribution at that time, and its gradual convergence with the present. 3) High-resolution palynological study shows that although some climatic events since the last glacial maximum have been documented in some stratigraphic profiles, they have limited impact on the overall nature of local vegetation. In addition to the global climate change, the vegetation in the study area is also affected by the evolution and development of monsoon climate. 4) Human activities are not clearly reflected in 9 ka BP and 6 ka BP vegetation maps, which indicates that early farming activities have little influence on the original vegetation. The impact of human activities on vegetation is generally earlier in the middle and lower reaches of the Yangtze River than in the other areas of southern China, and the impact is more distinct. 5) The rise of sea level during the Holocene megathermal might also affect the distribution of vegetation at that time. Large-scale transgressions were recorded in Lake Dongqian, Lake Baima and Lake Xianghu in the early Holocene. This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Wang W*, Li C, Shu J, Chen W. 2019. Changes of vegetation in southern China. Science China Earth Sciences, https://doi.org/10.1007/s11430-018-9364-9
Geographic location map of newly added boreholes and boreholes in documents. solid dots, Newly added boreholes; hollow dots, boreholes in documents
Vegetation zoning map in southern China. (a) Modern vegetation zoning map; (b) 18 ka BP vegetation zoning map; (c) 9 ka BP vegetation zoning map; (d) 6 ka BP vegetation zoning map Contact: Prof. Wang Weiming, Principal Investigator Email: wmwang@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
In recent years, a research team led by Prof. WANG Yongdong from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, and Dr. Tian Ning, an associate professor from Shenyang Normal University, carried out a comprehensive study on the Mesozoic wood fossils containing fungal mycelia with some update discoveries. Recently, two new reports from this team have been published on the journals Cretaceous Research and Acta Geologica Sinica (Chinese Edition). Structurally preserved petrified woods contain not only information of wood anatomy, but also plenty of physiological and ecological information, including trace fossils of insect boring, fungal hyphae and other micro-organisms. Study of these permineralized plants is helpful to reveal the ecological and co-evolutionary relationships among plants, insects, fungi and other organisms in geological past. Abundant and diverse Cretaceous wood fossils have been recorded in China. However, previous studies of petrified wood mainly focused on their anatomy and taxonomy, little work has been reported on the fungal remains and the interaction between the wood hosts and fungi. In recent years, a research team led by Prof. WANG Yongdong from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, and Dr. Tian Ning, an associate professor from Shenyang Normal University, carried out a comprehensive study on the Mesozoic wood fossils containing fungal mycelia with some update discoveries. Recently, two new reports from this team have been published on the journals Cretaceous Research and Acta Geologica Sinica (Chinese Edition)(cover story). Well-preserved fossil mycelium consisting of clamp-bearing septate hyphae is found in a petrified conifer wood (Cupressinoxylon baomiqiaoense Zheng et Zhang) from the Lower Cretaceous Yunshan Formation in Heilongjiang Province, NE China. The fungal hyphae are tubular in shape with septa and typical clamp-connections. Taxonomically, the occurrence of clamp-connections indicates that the present fungal remains should be referred to the Basidiomycota. Ecologically, the present fossil mycelium is proposed to be a saprotroph, i.e. a wood rotting fungus. The decomposition of the tracheary middle lamina of the wood host strongly implies that the present fungal mycelium to be a white-rotting fungus. Additionally, similar basidiomyceous fossils with white rot function were found in fossil conifer wood of Agathoxylon sp. from the Lower Cretaceous Guantou Formation in Xinchang of Zhejiang Province, SE China. The present new finding of basidiomyceous fossils represents the first unequivocal records of Cretaceous wood-rotting fungi, provides increasing data on the fossil diversity of fungi in China, and contributes to further understanding the plant-fungal interaction in the Cretaceous terrestrial ecosystem. Reference: Tian Ning*, Wang Yongdong*, Zheng Shaolin, Zhu Zhipeng, 2019. White-rotting fungus with clamp-connections in a coniferous wood from the Cretaceous of Heilongjiang Province, NE China. Cretaceous Research, doi.org/10.1016/j.cretres.2018.11.011 (*authors for correspondence) Zhu Zhipeng, Li Fengshuo, Xie Aowei, Tian Ning, Wang Yongdong, 2018. New record of Early Cretaceous petrified wood with fungal infection in Xinchang of Zhejiang Province, Acta Geologica Sinica-Chinese Edition, 92: 1149-1162 (cover story). Fungal hyphae from the Early Cretaceous petrified wood in Heilongjiang Province, NE China (Image by TIAN Ning) Fungal hyphae from the Early Cretaceous petrified wood in Heilongjiang Province, NE China (Image by TIAN Ning) Fungal hyphae from the Early Cretaceous petrified wood in Zhejiang Province, SE China (Image by ZHU Zhipeng) Contact: Prof. WANG Yongdong, Principal Investigator Email: ydwang@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
What exactly controlled the Cambrian Explosion has been a subject of scientific debate since Darwin’s time. Recently, a joint China-UK-Russia research team gives strong support to the hypothesis that the oxygen content of the atmosphere and ocean was the principal controlling factor in early animal evolution. Early Cambrian sections of the Lena River in Siberia (Image by ZHU Maoyan) The Cambrian Explosion around 540 million years ago was a key event in the evolutionary history of life. But what exactly controlled the Cambrian Explosion has been a subject of scientific debate since Darwin’s time. A multidisciplinary study, published on May 6 in Nature Geoscience by a joint China-UK-Russia research team, gives strong support to the hypothesis that the oxygen content of the atmosphere and ocean was the principal controlling factor in early animal evolution. In past decades, important fossil discoveries revealed a puzzling pattern of episodic radiations and extinctions in early animal evolution. This pattern coincides with dramatic fluctuations in the carbon isotopic composition of seawater, according to study co-author ZHU Maoyan from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences. Lower Cambrian strata along the Aldan and Lena rivers in Siberia consist of continuous sequences of limestone with abundant fossils and reliable age constraints, making these rocks ideal for analysing ancient seawater chemistry. The isotopic signatures of the rocks correlate with the global production of oxygen, allowing the team to determine oxygen levels in shallow sea water and the atmosphere during the Cambrian Period. The study is the first to show that the pattern of episodic radiations and extinctions in early animal evolution closely matches extreme changes in atmospheric and oceanic oxygen levels. This result strongly suggests that oxygen played a fundamental role in the Cambrian Explosion of animals. “The complex creatures that came about during the Cambrian Explosion were the precursors to many of the modern animals we see today. By analysing carbon and sulphur isotopes found in ancient rocks, we are able to trace oxygen variations in Earth’s atmosphere and shallow oceans during the Cambrian Explosion. We found that evolutionary radiations follow a pattern of ‘boom and bust’ in tandem with the oxygen levels,” said Dr. HE Tianchen, study lead author and postdoctoral researcher at the University of Leeds. According to Prof. Graham Shields, study co-author from UCL Earth Sciences, this is the first study to show clearly that our earliest animal ancestors experienced a series of evolutionary radiations and bottlenecks caused by extreme changes in atmospheric oxygen levels. The result was a veritable explosion of new animal forms during more than 13 million years of the Cambrian Period. Study co-author Dr. Benjamin Mills, from the School of Earth and Environment at Leeds, said, “The Siberian Platform gives us a unique window into early marine ecosystems. This area contains over half of all currently known fossilised diversity from the Cambrian Explosion.” “This has been an incredibly successful and exciting joint study. The question of the Cambrian Explosion trigger has puzzled scientists for years. Now, the results give us convincing evidence to link the rapid appearance of animals as well as mass extinction during the early Cambrian with oxygen,” said co-author Andrey Yu Zhuravlev from Lomonosov Moscow State University. Study co-author YANG Aihua from Nanjing University said, "In the last decade, progress has been made in the Cambrian Explosion; this study shows the interactions between the biodiversity of animal and environment during the early Cambrian." Contact CHEN Xiaozheng Nanjing Institute of Geology and Palaeontology E-mail: chxzh@nigpas.ac.cn DOI: https://doi.org/10.1038/s41561-019-0357-z
Prof. LI Chunxiang from Nanjing Institute of Geology and Palaeontology of Chinese Academy of Sciences and her colleagues analyzed the combined data of morphology and molecular data available to re-evaluate the systematic position of Coniopteris. The researchers therefore propose that Coniopteris may be more closely related with Polypodiales than with Dicksoniaceae, and Coniopteris is probably a stem group of Polypodiales. This interpretation is consistent with the vertical annuli of Coniopteris, an apparent synapomorphy of Polypodiales.It is generally recognized that the fossil records are incomplete in nature, yet fossils had very important impact on our development of evolutionary theory. The value of a particular fossil in contributing to our knowledge in evolutionary history for any lineage depends upon an adequate description of sufficient characters including synapomorphies, necessary for the accurate identification of its affinities or precise phylogenetic placement. Here is a case of such kind of study. The extinct fern genus Coniopteris was a typical component in the Mesozoic flora with a wide distribution in both Northern and Southern Hemispheres from Early Jurassic to Early Cretaceous, and it played a very important role in stratigraphic correlation, while its character evolution and systematic position have both been unsolved mysteries.Prof. LI Chunxiang from Nanjing Institute of Geology and Palaeontology of Chinese Academy of Sciences and her colleagues analyzed the combined data of morphology and molecular data available to re-evaluate the systematic position of Coniopteris.The study produced the results as: (1) all extant genera in Dicksoniaceae have bivalvate indusia, while most species of Coniopteris have cup-shaped indusia; (2) most Dicksoniaceae occur in the tropical zone, different from the temperate habitats for most Coniopteris species; (3) Coniopteris may be herbaceous, whereas extant Dicksoniaceae are mostly tree-like ferns; and (4) Dicksoniaceae and Thyrsopteridaceae all have oblique annuli, while most species of Coniopteris have vertical ones.Based on these differences, Coniopteris should not be treated in Dicksoniaceae. Its systematic position was further evaluated by a cladistic analysis using morphological characters of spore-producing organs and spores and integrated with studies of fern molecular phylogeny as a constraint (molecular backbone). The results show that Coniopteris is clustered with Dennstaedtia, Lindsaea, and Odontosoria, not with Calochlaena, Dicksonia, and Lophosoria in Dicksoniaceae.The researchers therefore propose that Coniopteris may be more closely related with Polypodiales than with Dicksoniaceae, and Coniopteris is probably a stem group of Polypodiales. This interpretation is consistent with the vertical annuli of Coniopteris, an apparent synapomorphy of Polypodiales.The research was supported by Project from Shanghai Landscaping & City Appearance Administrative Bureau (Grant No. G162422), Projects of State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of geology and Palaeontology, CAS) (Grant No. Y626040108), and Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB26000000). Reference: Chunxiang Li, Xinyuan Miao, Li-Bing Zhang, Junye Ma, Jiasheng Hao (2019). Re-evaluation of the systematic position of the Jurassic–Early Cretaceous fern genus Coniopteris. https://doi.org/10.1016/j.cretres.2019.04.007 Sori of Coniopteris (G) and related species of Dennstaedtia (A-D) and Calochlaena straminea (F). Image by LI Chunxiang.. Majority-rule consensus tree of Coniopteris and its related extant groups corresponding to cladistic analysis based on reproductive structure characters and a molecular phylogenetic tree for the extant taxa as constraints. Sporangia types among the main clades are indicated on the right side of the tree (note: annuli are in illustrated). Image plotted by LI Chunxiang. Contact: Prof. LI Chunxiang, Principal Investigator Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Abundant Triassic radiolarian fossils were obtained from varicolored bedded cherts exposed in the Buruocang section near Jinlu village, Zedong, southern Tibet. The radiolarian‐bearing rocks represent fragmented remnants of the Neotethys oceanic sediments belonging to the mélange complex of the east part of the Yarlung‐Tsangpo Suture Zone. Two new middle Late Anisian radiolarian assemblages recognized from this section named Oertlispongus inaequispinosus and Triassocampe deweveri, respectively, are compared with those known from Europe, Far East Russia, Japan, and Turkey. These Anisian radiolarian fossils are the first reported in southern Tibet and the oldest radiolarian record within the Yarlung‐Tsangpo Suture Zone. They improve time constraints for the evolution of Neotethys in southern Tibet. In recent years, abundant Triassic-Cretaceous radiolarian fossils have been collected within the Yarlung Zangbo Suture Zone (YTSZ) in Zedong area of southern Tibet by the research group of Prof. LUO Hui from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences. PhD candidate CHEN Dishu and others from Prof. Luo’s research group, in cooperation with Prof. Atsushi Matsuoka of Niigata University in Japan, documented an Anisian radiolarian fuana obtained from varicolored bedded cherts exposed in the Buruocang section near Jinlu village in Zedong recently. The radiolarian-bearing rocks represent fragmented remnants of the Neotethys oceanic sediments belonging to the mélange complex of the east part of the Yarlung-Tsangpo Suture Zone. Two new middle Late Anisian radiolarian assemblages recognized from this section named Oertlispongus inaequispinosus and Triassocampe deweveri, respectively, are compared with those known from Europe, Far East Russia, Japan, and Turkey. These Anisian radiolarian fossils are the first reported in southern Tibet and the oldest radiolarian record within the Yarlung-Tsangpo Suture Zone so far. They provide a valuable new age constraint and allow the researchers to infer the timing of the early stage of the Neotethyan evolution in southern Tibet. At least in the Anisian, the eastern YTSZ had a pelagic sedimentary environment. This research was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, National Natural Science Foundation of China and also in part by the Japan Society for the Promotion of Science KAKENHI. Reference: Chen D, Luo H, Wang X, Xu B, Matsuoka A. Late Anisian radiolarian assemblages from the Yarlung-Tsangpo Suture Zone in the Jinlu area, Zedong, southern Tibet: Implications for the evolution of Neotethys. Island Arc. 2019: 1–10. https://doi.org/10.1111/iar.12302 Outcrop photographs of Buruocang section of the bedded cherts, in Zedong , southern Tibet, Image by CHEN Dishu. Correlation of Triassic radiolarian zones and subzones, Image plotted by CHEN Dishu. Late Anisian radiolarians from Sample 14BRC-11 at the Buruocang section, Image by CHEN Dishu. Contact: Prof. LUO Hui PhD Corresponding author Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
