Cupules of Umkomasia mongolica of different size (probably aborted at different stages of development) The so-called “Mesozoic seed ferns”, a loose assemblage of extinct gymnosperms, are generally taken to comprise Caytonia, corystosperms and peltasperms. These three groups, together with the Permian glossopterids, have been considered of crucial importance for understanding the phylogeny of seed plants and the evolution of their key structural features, including especially the carpel and ovule of angiosperms. However, phylogenetic relationships among these groups, and their relationships to other lineages of living and fossil seed plants, remain uncertain, in large part because of incomplete knowledge and uncertain homologies among their reproductive organs. In a recent study, Dr. SHI Gongle from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and colleagues from the US, Mongolia, Japan and Germany described a new species of corystosperm seed-bearing organ, Umkomasia mongolica, based on abundant, three-dimensional lignified mesofossils from the Early Cretaceous of Mongolia. Individual seed-bearing units of U. mongolica consist of a bract subtending an axis that bifurcates, with each fork (cupule stalk) bearing a cupule near the tip. Each cupule is formed by the strongly reflexed cupule stalk and two lateral flaps that partially enclose an erect seed. The seed is borne at, or close to, the tip of the reflexed cupule stalk, with the micropyle oriented toward the stalk base.
Seed-bearing unit of Umkomasia mongolica from ventral and dorsal surfaces, showing the subtending bract (dark green), bifurcating axis (blue) and lateral flaps of cupules (light green) The corystosperm cupule is generally interpreted as a modified leaf that bears a seed on its abaxial surface. However, U. mongolica suggests that an earlier interpretation, in which the seed is borne directly on an axis (shoot), is equally likely. Current hypotheses of seed plant relationships place great weight on whether the seeds in different groups are borne “terminally on a shoot”, or adaxially or abaxially on modified leaves. For corystosperms, the axial interpretation suggested by U. mongolica, points to a possible relationship to Ginkgo, while the reflexed cupule may suggest a relationship to angiosperms. These two ideas may not be incompatible. If the fundamental phylogenetic division between angiosperms and all extant gymnosperms is correct, as suggested by analyses of molecular data, then corystosperms, Caytonia and perhaps other extinct groups, may be close to the point at which the two extant clades diverged. Reference: Shi G., Leslie A.B., Herendeen P.S., Herrera F., Ichinnorov N., Takahashi M., Knopf P., Crane P.R., 2016. Early Cretaceous Umkomasia from Mongolia: Implication for homology of corystosperm cupules. New Phytologist 210: 1418-1429.
Fungal hyphae in the fossil wood from the upper Permian of Xinjiang Fungi and oribatid mites are major decomposers of higher plants in modern ecosystem. The interactions among oribatid mites, fungi and plants in terrestrial ecosystems have been well documented during the late Paleozoic. However, previous records have been observed mainly from materials of Euramerican and Gondwanan floras, providing little information on the mid-latitude Angara Flora.
Decaying processes in the fossil wood Recently, Dr. WAN Mingli and Prof. WANG Jun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences documented several lines of evidence of plant-arthropod and plant-fungus interactions from the Wuchiapingian in Turpan-Hami Basin, Xinjiang, northwestern China. Fossil wood, Septomedullopitys szei Wan, Yang et Wang, contains differentially-damaged areas. Spindle-shaped pockets in the fossil wood occur in the secondary xylem are commonly free of organic remains. They are comparable in appearance to modern white-pocket rot caused by fungi. The tracheid walls around the decomposed areas are degraded from the middle lamellae to outer layers. Abundant branching and septate fungal hyphae in the decayed areas, ray parenchyma and tracheid lumens indicate that fungi are responsible for the wood decay. These fungi are partially regarded as basidiomycetes because of the occurrence of clamp connections. According to the characteristic damages they caused to the host, ascomycetes are also viable candidates of the fungi because large parts of hyphae are without certain clamp connections. The other damaged excavations are the branched and maze-like borings and galleries, which are filled with abundant fungal hyphae, cellular debris and spheroidal to ovoidal, dark-colored coprolites. The size, shape, surface texture of these coprolites indicates that the coprolites are the feces of ancient oribatid mites. The fungal hyphae, coprolites, and degraded excavations in the pith of the late Permian wood suggest that wood-rotting and -boring were not limited to the xylem. Results of this study provide important information about the co-occurrence of plant-arthropod and plant-fungus interactions in the late Permian, and demonstrate the complexity of the terrestrial ecosystems at the east coast of mid-latitude northeastern Pangea.
Coprolites and borings in the fossil wood This work is supported by Chinese Academy of Sciences, State Key Laboratory of Palaeobiology and Stratigraphy, and the National Natural Science Foundation of China. Related information of this paper: Mingli Wan, Wan Yang, Lujun Liu, Jun Wang*, 2016. Plant-arthropod and plant-fungus interactions in late Permian gymnospermous woods from the Bogda Mountains, Xinjiang, northwestern China. Review of Palaeobotany and Palynology, 235: 120-128. doi: 10.1016/j.revpalbo.2016.10.003.
Photomicrographs of the labechiid stromatoporoid Cystostroma Stromatoporoid-grade sponges are among the most prominent metazoan builders in mid-Palaeozoic reefs. There are several records of stromatoporoid-like skeletal fossils in the Cambrian. However, none of them appear to be stromatoporoids sensu stricto. Pulchrilamina, the earliest putative Ordovician stromatoporoid, appeared in late Tremadocian-Floian reefs, which is much earlier than the diversification of other stromatoporoids. Based on the updated studies of Pulchrilaminida, most authors regarded pulchrilaminids as a separate, independent group of hypercalcified sponges rather than true stromatoporoids. The earliest undoubted stromatoporoids are assigned to the order Labechiida, which were thought to have emerged in the late Middle Ordovician (mid-late Darriwilian) after which they underwent a rapid diversification. Recently, Dr. LI Qijian from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his collegues reported the oldest known stromatoporoids (Cystostroma) and the cryptic keratose sponges in one of the lithistid sponge-Calathium reefs from the Lower Ordovician Hunghuayuan Formation at Zhangzhai (Guizhou, South China). This is also the first report of Ordovician labechiid stromatoporoids from South China.
Thin section micrographs of Calathium and associated biota These earliest stromatoporoids may have originated in reefs, which implies that the complex topography created by the hypercalcified sponge Calathium facilitated the emergence of stromatoporoids. Beyond Cystostroma, keratose sponges, Pulchrilamina (hypercalcified sponge) and bryozoans have also inhabited in the microhabitats (cavities and hard substrates) provided by Calathium. These findings suggest that ecosystem engineering by Calathium played an important role in the further diversification of reefs during the Ordovician. The study entitled “The oldest labechiid stromatoporoids from intraskeletal crypts in lithistid sponge-Calathium reefs” has been published online in Lethaia, doi: 10.1111/let.12182.
FLM and SEM images of Cereusisporites mirabilis Lu et Ouyang, 1978 The Middle Devonian represents an important period for the diversification and evolution of heterosporous plants. It has been shown that plants from this group evolved independently in several clades, as indicated by the diverse megaspore assemblages from this period, as well as by the Givetian occurrence of extreme forms of heterospory such as the seed megaspore. Lycopsid megaspores isolated from the Middle Devonian, Givetian, Shangshuanghe Formation at Qujing in Yunnan, Southwest China, were identified and illustrated by PENG Huiping, Dr. LIU Feng and Prof. ZHU Huaicheng from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences. Three species (Longhuashanispora reticuloides Lu et Ouyang, 1978, Ocksisporites maclarenii Chaloner, 1959, and Cereusisporites mirabilis Lu et Ouyang, 1978) are described. Comparisons with in situ spores produced by plant fossils recovered from coeval horizons in adjoining region suggest that Longhuashanispora reticuloides shares ultrastructural and morphological characteristics of the in situ spores yielded by both heterosporous and homosporous ligulate lycopsids. Its parent plant probably represents a transitional form from the homosporous ligulate to the heterosporous ligulate lycopsids. It supports the previous conclusion that the homosporous ligulate lycopsid lineage and the heterosporous ligulate lycopsid lineage have diverged in the late Middle Devonian. The parent plants of O. maclarenii and C. mirabilis may have been a type of herbaceous lycopsid, which is rarely preserved as a fossil. Furthermore, The presence of the genus Ocksisporites in South China, Arctic Canada, and northern Poland indicates that in the Middle Devonian a migration pathway for plants existed between South China and Laurasia. This work was funded by the National Natural Science Foundation of China. Reference: Peng, H.P., Liu F.*, Zhu, H.C (2016): Morphology and ultrastructure of Middle Devonian dispersed megaspores from Qujing, Yunnan, Southwest China. Review of Palaeobotany and Palynology, 234. 110-124.
Longitudinal (1–3) and transverse (4–9) thin sections of Catenipora Lamarck, 1816 from the Xiazhen Formation at Zhuzhai, South China Catenipora is one of the most common tabulate coral genera occurring in various lithofacies in the Upper Ordovician Xiazhen Formation at Zhuzhai in South China. A combination of traditional multivariate analysis and geometric morphometrics is applied to a large number of specimens to distinguish and identify species, by Dr. LIANG Kun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues. Based on three major principal components extracted from 11 morphological characters, three major groups as determined by the cluster-analysis dendrogram are considered to be morphospecies. Their validity and distinctiveness are confirmed by discriminant analysis, descriptive statistics, and bivariate plots. Tabularium area and common wall thickness are the most meaningful characters to distinguish the three morphospecies. Geometric morphometrics is adopted to compare the morphospecies with types and/or figured specimens of species previously reported from the vicinity of Zhuzhai. Despite discrepancies in corallite size, principal component analysis and discriminant analysis, as well as consideration of overall morphological characteristics, indicate that the morphospecies represent C. zhejiangensis Yu in Yu et al., 1963, C. shiyangensis Lin and Chow, 1977, and C. dianbiancunensis Lin and Chow, 1977. Catenipora occurs in seven stratigraphic intervals in the Xiazhen Formation at Zhuzhai, representing a variety of heterogeneous environments. The coralla preservation is variable due to differential compaction; coralla preserved in limestones are commonly intact and in growth position, whereas those in shales are mostly crushed or fragmentary. The size and shape of corallites are considered primarily to be species-specific characters, but are also related to the depositional environments. In all species, morphological characters including corallite size, septal development, and shape and size of lacunae show high variability in accordance with lithofacies and stratigraphic position. The intraspecific differences in corallite size at various localities in the Zhuzhai area may indicate responses to local environmental factors, but may also reflect genetic differences if there was limited connection among populations. The study has been published on Journal of Paleontology. Reference: Kun Liang, Robert J. Elias, Suk-Joo Choh, Dong-Chan Lee, Dong-Jin Lee, (in press). Morphometrics and paleoecology of Catenipora (Tabulata) from the Xiazhen Foramtion (Upper Ordovician), Zhuzhai, South China. Journal of Paleontology.
Fossil Podozamites leaf An international team leading by Prof. WANG Yongdong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) has conducted positive research progresses on biodiversity origin and radiation evolution of an extinct conifer plant (Podozamites) of the Mesozoic. Dr. Mike Pole, visiting professorship research fellow of the Chinese Academy of Sciences from New Zealand, collaborated with WANG Yongdong, as well as other Russian and Chinese researchers, have investigated on the rise and demise process of this plant group known more than 17 years ago in East Asia. This result was recently published online on the international geoscience journal Palaeogeography, Palaeoclimatology, Palaeoecology. The distribution pattern of Podozamites during the Jurassic period in East Asia Podozamites is a common morpho-genus established by Braun in 1843, which is used describing deciduous, shoot-dropping conifer with broad, multi-veined leaves. Morphologically, Podozamites is represented today by Agathis (Araucariacae) and Nageia (Podocarpaceae). It is indicated that during the Late Triassic–Early Jurassic, forests dominated by Podozamites were extensive in the mid-latitudes of eastern Asia. They appear to have been little-effected through the Triassic-Jurassic transition, but responded to climate changes later in the Jurassic. Progressively dried through the Middle Jurassic and aridity had developed in some areas in China by the Late Jurassic-Early Cretaceous, and the distribution center of Podozamites shifted north, to the Siberian region. By the late Albian, angiosperms had arrived in the Siberian area and risen to dominance. After this event, Podozamites became extinct. It is unexpected that as broad-leaved angiosperms took over, amongst the conifers it was the broad leaved, multi-veined Podozamites became extinct. This is the morphology that might have been expected to compete with the apparently more shade-forming angiosperms. This new results provide significant fossil evidence for exploring the co-evolution and radiation relationships for Mesozoic conifers and early angiosperms. This study was funded by the State Key Project of Ministry of Science and Technology, the international visiting professorship and National Natural Science Foundation of China. Article information: Pole, M., Wang Y.D.*, Bugdaeva, E., Dong C., Tian N., Li L.Q., Zhou N., 2016. The rise and demise of Podozamites in east Asia—An extinct conifer life style. Palaeogeography, Palaeoclimatology, Palaeoecology A schematic interpretation of Podozamites and angiosperm distribution in Siberia around the mid-Cretaceous transition to an angiosperm-dominated flora
The superorder Odonatoptera consists of the extinct orders Geroptera and Protodonata, and the recent order Odonata. Odonatoptera belongs to medium-large insect, is the pioneer conquering the sky, and has been the giant insect with the wing spans over half meter. The dragonfly has strong fly ability, fast migration, wide distribution, which can help us correlate the strata and evaluate the influence of the vital geological and ecological events on insect evolution. Due to the large size and few number, rare dragonflies can be preserved as the fossil records. Recently, the Mesozoic research group of our institute cooperates with The University of Hong Kong, and mades a detailed study on the Mesozoic Odonatoptera. The specimens were from the Triassic of Shaanxi, the Jurassic of Xinjiang, the Lower Cretaceous of Inner Mongolia, western Liaoning, and Cretaceous Burmese amber. 11 new species, 6 new genera and 1 new subfamily were established relating to 11 families. This research can contribute to the correlation of Chinese non-marine strata, and providing new evidence for the origination, evolution and radiation of dragonflies. Represented findings are as follows: 1. The first Triassic Protodonata from China. Although abundant dragonfly fossils have been reported from the Middle Jurassic–Lower Cretaceous, no Triassic dragonflies have been recorded. In the past years, we unearthed one protodonatan dragonfly, representing the first discovery. The fossil genera has been previously recorded in the Madygen Formation of Kyrgyzstan. Combined with the palaeontological and geochronological evidence, the age of the Tongchuan Formation is considered to be Anisian–Early Carnian, and the insect-bearing layers are considered to be Ladinian. 2. The first earliest Jurassic Odonata. The fossil was collected from the middle part of the Upper Triassic-Lower Jurassic Badaowan Formation. The similar damsel-dragonfly was initially described from the Lower Jurassic (Lower Lias, lowermost Sinemurian) of Dorset, England, reflecting the close relationship between these two insect assemblages. The latitude of the Junggar Basin during the T-J interval was considered to be around 60° N, while England was located at 30–40° N, suggesting a long distance between the two areas. The appearance of the damsel-dragonfly in two localities probably reflect a weak influence of the end-Triassic extinction on damsel-dragonflies or a quick dispersal of damsel-dragonflies during the earliest Jurassic. 3. Diversity of extinct family Stenophlebiidae. Stenophlebiidae has been found widely distributed in the Jurassic-Cretaceous strata of Germany, Spain, England, France, China, Mongolia and Kazakhstan. Until now, only one unquestioned stenophlebiid damsel-dragonfly has been recorded from the Lower Cretaceous Yixian Formation of the Liutiaogou outcrop in Inner Mongolia. Liaostenophlebia yixianensis Zheng et al., 2016 is a new genus of this family. Except S. karatavica from the Jurassic of Kazakhstan, Stenophlebia is known by several species from the Upper Jurassic of Europe. The new species S. liaoxiensis Zheng et al., 2016, from the Lower Cretaceous of Liaoning, extends the range both stratigraphically and geographically of this extinct dragonflies. 4、New dragonfly and damselfly from mid-Cretaceous Burmese amber. The study of the insect inclusions in Burmese amber is about a century old, but the odonatans were just from 2010. In the recent years, as more insect inclusions discovered from Burmese amber, three suborders of the recent Odonata were reported represented by Zygoptera (damselfly). The main findings include: the second true dragonfly from Cretaceous amber; the first Hemiphlebiidae may be the most common damselfly in Burmese amber with over 50 specimens having been observed; the earliest fossil platystictid damselfly puts the origin of Platystictidae to at least mid-Cretaceous in tropical forest; the first fossil Perilestidae; a new species of Platycnemididae; a new subfamily and two new genera of the extinct family Dysagrionidae with unique discoidal cell contributing to the evolution of damselfly wings. The study were published (including accepted) in the following geological journals: Geological Magazine, Journal of Paleontology, Cretaceous Research, Proceedings of the Geologists' Association, Comptes Rendus Palevol and Alcheringa. Related information of these research: Zheng, D.R., Nel, A., Wang, B., Jarzembowski, E.A., Chang, S.-C., Zhang, H.C. (in press). The first Triassic “Protodonatan” (Zygophlebiidae) from China: stratigraphical implications. Geological Magazine, http://dx.doi.org/10.1017/S0016756816000625. Zheng, D.R., Zhang, Q.Q., Jarzembowski, E.A, Zhou, Z.C., Chang, S.-C., Wang, B., Nel, A. (in press). New damselflies (Odonata: Zygoptera: Hemiphlebiidae, Dysagrionidae) from mid-Cretaceous Burmese amber. Alcheringa: An Australasian Journal of Palaeontology, http://dx.doi.org/10.1080/03115518.2016.1164402. Zheng, D.R., Jarzembowski, E.A., Chang, S-C., Wang, B. (in press). A new true dragonfly (Odonata, Anisoptera, Gomphaeschnaoidini) from mid-Cretaceous Burmese amber. Proceedings of the Geologists' Association, http://dx.doi.org/10.1016/j.pgeola.2016.07.006. Zheng, D.R., Wang, B., Chang, S-C. (in press). Palaeodisparoneura cretacica sp. nov., a new damselfly (Odonata: Zygoptera: Platycnemididae) from mid-Cretaceous Burmese amber. Comptes Rendus Palevol, doi: 10.1016/j.crpv.2016.08.005. Zheng, D.R., Nel, A., Wang, B., Jarzembowski, E.A., Chang, S.-C., Zhang, H.C., 2016. A new damsel-dragonfly from the Lower Jurassic of northwestern China and its palaeobiogeographic significance. Journal of Paleontology, 90 (3): 485–490. Zheng, D.R., Wang, H., Jarzembowski, E.A., Wang, B., Chang, S.-C., Zhang, H.C., 2016. New data on Early Cretaceous odonatans (Stenophlebiidae, Aeschnidiidae) from northern China. Cretaceous Research, 67: 59–65. Zheng, D.R., Wang, B., Jarzembowski, E.A., Chang, S.-C., Nel, A., 2016. Burmadysagrioninae, a new subfamily (Odonata: Zygoptera: Dysagrionidae) from mid-Cretaceous Burmese amber. Cretaceous Research, 67: 126–132. Zheng, D.R., Zhang, Q.Q., Chang, S.-C., Wang, B., 2016. A new damselfly (Odonata: Zygoptera: Platystictidae) from mid-Cretaceous Burmese amber. Cretaceous Research, 63: 142–147. Zheng, D.R., Wang, B., Jarzembowski, E.A., Chang, S.-C., Nel, A., 2016. The first fossil Perilestidae (Odonata: Zygoptera) from mid-Cretaceous Burmese amber. Cretaceous Research, 65: 199–205. Zheng, D.R., Nel, A., Wang, B., Jarzembowski, E.A., Chang, S.-C., Zhang, H.C., 2016. The first Early Cretaceous damsel-dragonfly (Stenophlebiidae: Stenophlebia) from western Liaoning, China. Cretaceous Research, 61: 124–128. Zheng, D.R., Nel, A., Wang, B., Jarzembowski, E.A., Chang, S.-C., Zhang, H.C., 2016. The discovery of the hindwing of the Early Cretaceous dragonfly Sinaktassia tangi Lin, Nel & Huang, 2010 (Odonata, Aktassiidae) in northeastern China. Cretaceous Research, 61: 86–90.
Figure 1. Mesozoic Odonatoptera from north China, scale bars = 10 mm. A, Sinaktassia tangi Lin, Nel & Huang, 2010; B, Stenophlebia liaoningensis Zheng et al., 2016; C, Dorsettia sinica Zheng et al., 2016; D, Zygophlebia tongchuanensis Zheng et al., 2016; E, Liaostenophlebia yixianensis Zheng et al., 2016; F, Sinostenophlebia zhanjiakouensis Hong, 1984.
Figure 2. Odonata from mid-Cretaceous Burmese amber, scale bars = 2 mm. A–B, Burmahemiphlebia zhangi Zheng et al., 2016; C, Palaeodysagrion cretacicus Zheng et al., 2016; D, Palaeodisparoneura cretacica Zheng et al., 2016; E, Burmadysagrion zhangi Zheng, Wang and Nel, 2016; F, Mesosticta electronica Zheng et al., 2016; G, Cretagomphaeschnaoides jarzembowskae Zheng et al., 2016; H, Palaeoperilestes electronicus Zheng et al., 2016.
Energy Dispersive Spectrometer (EDS) elementalmapping for a globose Chuaria (A)–(D), and a subglobose Chuaria (E)–(H); linear elementalmapping for a globose Chuaria (I) and a subglobose Chuaria (J) Pyritization represents a major taphonomic pathway for exceptional preservation of soft tissues. Although various Ediacaran Lagerst？tten contain pyritized fossils, the controls on this taphonomic pathway prior to the Precambrian-Phanerozoic transition have only recently received significant attention, and no studies have yet thoroughly investigated environmental conditions facilitating exceptional preservation via pyritization in the early Ediacaran. Here, to address this deficiency, Dr. GUAN Chengguo from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues investigated the preservational environments of macroscopic fossil Chuaria in the early Ediacaran Lantian Formation of South China using petrographic, electron microscopic, and geochemical data. Chuaria occur as pervasively pyritized (spheroid-shaped) globose and non-pervasively pyritized (disk-shaped) subglobose fossils in different stratigraphic intervals. Although these different stratigraphic intervals are similar in terms of total sulfur (TS, ~5%), subglobose Chuaria shales have greater total organic carbon (TOC, ~7.9%) contents than globose Chuaria shales (~3.6%). Additionally, petrographic observations and TOC-TS cross-plots suggest that, whereas globose fossils were preserved under suboxic bottom waters, the subglobose fossils were preserved in euxinic bottom waters. Stratigraphy, TOC, TS and δ34Spy values, and their relationship with the preservation types of Chuaria fossils in the Lantian Formation. Overall, these results affirm that pyritization in the Precambrian was generally favored in organic-poor, reactive iron-rich, sulfate-rich environments probably with slow sedimentation rates. When organics were scarce and reactive iron was abundant, bacterial sulfate reduction (BSR) created hydrogen sulfide and reactive iron concentration gradients around fossils, which kinetically and thermo-dynamically favored rapid and pervasive pyritization, as observed in globose Chuaria. Conversely, when organics were abundant and reactive iron/sulfate availabilities were limited by widespread BSR, fossils were relatively rapidly buried beneath the BSR metabolic zone of sediment, where they were principally preserved as aluminosilicified carbonaceous fossils that were compacted into subglobose forms. Thus, preservational variations among pyritized fossils in the Ediacaran may reflect differences in sedimentary organic matter content and/or bottom water redox chemistry. This research was supported by Chinese Academy of Sciences, the National Natural Science Foundation of China, State Key Laboratory of Palaeobiology and Stratigraphy (LPS) and Natural Science Foundation of Jiangsu Province of China. Related information of this paper: Guan, C., Wang, W., Zhou, C., Muscente, A.D., Wan, B., Chen, X., Yuan, X., Chen, Z. and Ouyang, Q. Controls on fossil pyritization: Redox conditions, sedimentary organic matter content, and Chuaria preservation in the Ediacaran Lantian Biota. Palaeogeography, Palaeoclimatology, Palaeoecology.
Surface renderings and digital sections of three embryo-like fossils (Doushantuo Formation, South China) The origin and early evolution of animals have been a fascinating issue since Charles Darwin. Calculating molecular divergences and decoding fossil records are two significant approaches to address this mystery issue. Current data from the two approaches, however, have resulted in different perspectives on this issue. The molecular clocks estimated that animals may have arisen 750 million years ago (Ma), yet the first definite animal fossils occurred during very late Ediacaran, probably no more than 555 Ma. Under this background, the ca. 600 million-year-old Ediacaran embryo-like fossils from South China provide a compelling case to reconcile the inconsistency of the two approaches because they were ever taken as early animal remains. However, their affinities are still in debate. Recently, Dr. YIN Zongjun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues reported new fossil forms from the Ediacaran Doushantuo phosphorite from South China. They used high-resolution synchrotron radiation X-ray microtomography to reconstruct three-dimensional structures of the fossils, and the results demonstrate that these fossils preserve features directly comparable to living animal embryos that utilize discoidal-type incomplete cell division. This find suggests that some Ediacaran embryo-like fossils are likely embryos of animals. Animals probably have arisen on the planet as early as ca. 600 million years ago. The study has been published on Geology. Reference: Zongjun Yin*, Maoyan Zhu, David J. Bottjer, Fangchen Zhao, Paul Tafforeau. Meroblastic cleavage identifies some Ediacaran Doushantuo (China) embryo-like fossils as metazoans. Geology. DOI: 10.1130/G38262.1
Coral faunal turnover across the Ordovician–Silurian transition in South China The end-Ordovician glaciation has widely been regarded as having profound influence on the biogeographic distribution of shelly fauna, as shown by time equivalence of brachiopods of the tropical Edgewood province with those of the higher-latitude Kosov and Bani provinces. Recent investigation conducted by Dr. WANG Guangxu fromNanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues reveals an adaptive phase during the Hirnantian glaciation, followed by an early survival phase and finally a late survival phase that persisted into the early Silurian. They demonstrate that a coral assemblage of latest Hirnantian to earliest Silurian age, remarkably similar to those from the Edgewood fauna known from Laurentia, occurs stratigraphically above the typical Hirnantian fauna. This, in combination with other evidence (e.g. brachiopods, lithology and chemostratigraphy), suggests the Edgewood fauna probably post-dated the early–middle Hirnantian glaciation, rather than being coeval with the older glacial-related Hirnantia fauna. Evidence from South China shows that the Edgewood fauna appeared in the very latest Hirnantian and extended into the middle Rhuddanian, considerably younger than previously believed. Such a new correlation necessitates a reassessment of the influence of the end-Ordovician glaciation on biotas. They argue that this major glaciation probably would have substantially affected the ecosystem even in tropical regions, as shown by the development there of the Hirnantia fauna or, alternatively, the presence of a conspicuous stratigraphic hiatus. This suggests a surprisingly rapid biotic recovery during the subsequent postglacial transgression, represented by the flourishing of comparatively diverse shelly faunas (e.g. the Edgewood fauna and the Cathaysiorthis brachiopod fauna) in nearshore shallow water environments from Laurentia to eastern peri-Gondwana terranes or blocks (e.g. South China).
Possible relationships between the bio-events and glaciation through the Ordovician–Silurian transition Related information of this paper: Wang G. X, Zhan R. B., Huang B., Percival I. G. 2016 (published online). Coral faunal turnover through the Ordovician-Silurian transition in South China and its global implications for carbonate stratigraphy and macroevolution. Geological Magazine (doi:10.1017/S0016756816000406)
