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    2022,61(4):525-540, DOI: 10.19800/j.cnki.aps.2021059
    Abstract:
    Silurian graptolite-bearing strata in Nyalam County are one of the few known sources of Silurian graptolites in southern Xizang (Tibet). Recent graptolite collections from the Shiqipo Formation at Yalai Village, Nyalam County, contain Normalograptus sp., Glyptograptus sp., Campograptus lobiferus, C. cf. lobiferus, C. cf. obtusus, C.? circularis, Lituigraptus cf. convolutus, Rastrites cf. perfectus, Stimulograptus sedgwickii, Streptograptus sp. and Torquigraptus decipiens. This assemblage indicates a late Aeronian (Llandovery) age (Lituigraptus convolutus to Stimu- lograptus sedgwickii biozones). This new finding provides the potential for the correlation of Silurian strata between Xizang (Tibet) and other parts of the world.
    2022,61(4):541-557, DOI: 10.19800/j.cnki.aps.2022023
    Abstract:
    Scleractinia are the major members of the Mesozoic, Cenozoic, and extant corals. Scleractinian corals are distinguished by their calcareous external skeletons. Scleractinian corals may be divided into two ecological groups: hermatypic (reef-building) and ahermatypic corals. Hermatypic corals are characterized by the presence of vast numbers of zooxanthellae in their endodermal tissues. They are the most common in warm and shallow marine waters of the tropics. Strong sunlight is essential for the vigorous growth of hermatypic corals. Ahermatypic corals lack zooxanthellae and are environmentally less restricted than reef-building corals. It is now generally recognized that, since the Miocene, there are two first-level reef-coral biogeographic provinces, i.e., the Caribbean and Indo-Pacific, in the world. The South China Sea, including Xisha Islands, is attributed to the Indo-Pacific Province. During the Neogene and Quaternary, the Indo-Pacific coral faunas were already rich than those of the Caribbean. The oldest coral-bearing beds are from the early Miocene in Xisha Islands, South China Sea. About 19 genera of Miocene scleractinian corals are recognized from the 364–878.3 m interval in the Well CK-2 core from Chenhang Island, Xisha Islands, South China Sea. They are Acropora, Astreopora, Antillophyllia, Antillia, Astrhelia, Caryophyllia, Cyphastrea, Diploastrea, Echinophyllia, Favia, Favites, Fungia, Galexea, Goniopora, Hydnophora, Montipora, Platygyra, Porites and Turbinaria. Among them, the geological ranges of the genera Echinophyllia, Fungia and Galaxea are from the Miocene to the Quaternary, indicating that the age of the strata that yield these three genera is not older than the Miocene. While the genus Antillia has been recorded from the Eocene to the Miocene and the genus Antillophyllia has been reported from the Oligocene to the Miocene, indicating that the age of the strata that contain these two genera is not younger than Miocene. Moreover, the genus Astrhelia has hitherto been known only from the Miocene. All the above-mentioned evidence suggests a Miocene age. About 21 genera of the Pleistocene scleractinian corals and one genus of Octocorallia are identified from the 21.4–215.6 m interval in the Well CK-2 core. Among them, the geological ranges of Acanthophyllia, Enallopsammia, Fungia, and Galaxea are from the Miocene to the Quaternary. The genera Acoropora, Coenocythus, Cyphastrea, Euphyllia, Montipora, Pavona, Porites, Favites, Goniastrea, Platygyra and Turbinaria have been recorded from the Palaeogene to the Quaternary and the genera Astreopora, Goniopora and Leptoria are the characteristic corals from the Cretaceous to the Quaternary. A few genera, however, afford evidence of considerable weight for the determination of the age of the strata. The three scleractinian corals, i.e., Lobophyllia, Symphyllia, and Trochopsammia, and the octocoral genus Heliopora have hitherto been known only from the Quaternary. The above evidence suggests that the age of the coral assemblage is Quaternary (Pleistocene). Since very few Miocene and Pleistocene corals have been reported previously from the Xisha Islands, a brief description of these fossils is warranted in the paper.
    2022,61(4):558-567, DOI: 10.19800/j.cnki.aps.2021071
    Abstract:
    Sphenothallus Hall, 1847, a genus of benthic Cnidaria characterized by elongate cones and tubes, first occurred in the Cambrian and extended to the Permian. This genus has been reported from the Niutitang Formation (Stage 3, Series 2), Tsinghsutung Formation (Stage 4, Series 2), and the Kaili Formation (Wuliuan Stage, Miaolingian Series) in Guizhou Province. It has also been recently discovered in the Balang Formation (Stage 4, Series 2). Based on the characteristics of these tubular fossil specimens, two species, S. kozaki and S. kozaki?, are described from the Balang Formation.Previously, Sphenothallus kozaki was only found in the Jince Formation of the Czech Republic and the Shipai Formation of Hubei Province of South China. Compared with other species of this genus, S. kozaki possesses a long, narrow, straight, conical tube with a circular cross-section and insignificant thickening marks on the inner wall, indicating that the wall of S. kozaki is thin and weak. No transverse striae on the longitudinal thickening are observed. These tubes are straight throughout their length and have a very small angle of expansion. The longitudinal thickenings are not prominent in these specimens. Sphenothallus kozaki? has smaller expansion angles compared with S. kozaki, and the extension from the base to the upper carapace is approximately parallel. The specimens of S. kozaki? have multiple inclined, irregular, longitudinal ridges inside, presumably resulted from taphonomic bias. We describe the holdfast morphology of Sphenothallus kozaki and S. kozaki? and analyze their attachment strategies, providing useful information on the dynamics of of substrate conditions in the Cambrian. The apices of S. kozaki and S. kozaki? specimens from the Balang Formation are conical, and the basal attachment disks are not preserved. These characteristics suggest that the attachment strategies of these specimens are different from other genera. The result shows that S. kozaki and S. kozaki? rely on self-weight to insert their tips into the soft seafloor, anchoring themselves to the soft substrates. The majority of S. kozaki and S. kozaki? specimens are found in mudstone, confirming this observation. Some species of the Cambrian Sphenothallus evolved discoidal holdfast, whereas most post-Cambrian species of the genus are found with discoidal holdfast, possibly indicating that different species of the genus had different attachment strategies during the Cambrian. This change might be an adaptive response to varying substrate conditions during the Cambrian. Comparative analysis of the depositional environments indicates that both the Jince Formation and Shipai Formation are shallow-water platform facies, while the Balang Formation is a deep-water slope belt facies. The new discovery of S. kozaki in the Balang Formation suggests that this species is well adapted to different water depths and is, therefore, more widely distributed. The discovery also provides new information on the cnidarian, evolution, geographic distribution and species diversity of Sphenothallus during the Stage 4 Age (Series 2, Cambrian), and in understanding the benthic community composition of the Balang Biota.
    2022,61(4):568-589, DOI: 10.19800/j.cnki.aps.2021071
    Abstract:
    Hundreds of specimens of saukiid trilobites were collected from the middle?upper Chaumitien Formation (upper Jiangshanian through Stage 10, Cambrian) at Fenghuangshan Hill in northern Anhui, China. Four genera and six species (including two new species) are described herein: Eosaukia bella (Walcott, 1906), E. anhuiensis sp. nov., Lophosaukia orientalis (Kobayashi, 1933), Prosaukia campe (Walcott, 1905) and P. xiaoxianensis sp. nov., Lichengia onigawara Kobayashi, 1942. After revising and discussing the generic diagnoses, we reexamine and revise the specific diagnoses of the four previously-published species by comparing their type species with others, and briefly discuss the evolutionary relationships among all six species.
    2022,61(4):590-602, DOI: 10.19800/j.cnki.aps.2021050
    Abstract:
    Crinoid fragments and ossicles are very common in Ordovician carbonate rocks of the Tazhong Platform, Tarim Basin, Northwest China. In this paper, which differs from the previous studies that focused on intact crinoid fossils, we present a comprehensive analysis of the types and contents of the crinoid stem fossils including ossicles and fragments, and the taphonomy of the symbiotic animals from the Upper Ordovician core of Well Tazhong 35, as well as the sedimentary environments in order to understand the paleoecology of the crinoids. From the core samples, seven types of ossicles are identified: Cyclocyclicus, Pentagonopentagonalis, Pentagonocyclicus, Ellipsocyclicus, Pentagonoellipticus, round Pentagonopentagonalis, and irregular Pentagonopentagonalis. Four ossicle assemblages are recognized: Pentameri, Elliptici, Cyclici and Varii. Results of the statistic analysis of the shape, size and percentage of the ossicles, combined with the taphonomic characteristics of the symbiotic animals and analysis of the sedimentary environments, indicate that crinoids are absent from the community dominated by cyanobacteria and tetradiids in the restricted lagoon environment. Very few slim crinoid ossicles occurr in the biota of gastropods and ostracods in the fine-grained bank facies covering the lagoon facies. Abundant crinoids and various symbiotic bryozoans, Solenopora, dasycladaceans and other organisms are present in the biota of the open platform facies. Both crinoids and bryozoans are filter feeders, and should have a symbiotic but competition relationship in most cases. However, in the Ordovician Tazhong sea, the difference in their body size determines the two groups belong to different filter feeding groups, which eases the competition between them. In communities dominated by crinoids and bryozoans, crinoid ossicles are the most abundant, and all four ossicle assemblages are present. Solenopora is photosynthetic, it has no competition with the crinoids, and its relationship with the crinoids is mutualistic. The crinoid ossicles in the Solenopora–crinoid community belong to the Cyclici type. They are relatively simple, big, and dense, and their content is the highest. The crinoids are widely symbiotic with the dasycladaceans. Due to the influence of the oncoids formed by filamentous cyanobacteria, the number and size of crinoid ossicles and fragments are smaller than those of the dasycladaceans, but they are relatively richer and more diverse, including all four types. Therefore, we suggest that the most suitable environment is the open platform for the Upper Ordovician crinoids from Well Tazhong 35, and the main controlling factors are hydrodynamic energy and water cleanliness. The crinoids flourish more in cleaner water with higher hydrodynamic energy, while turbulent water with low hydrodynamic energy is disadvantageous to their survival.
    2022,61(4):603-614, DOI: 10.19800/j.cnki.aps.2022001
    Abstract:
    Ichnofossils provide invaluable information in understanding the process of colonization of infauna in the shallow-marine shelf settings during the Great Ordovician Biodiversification Event. The ichnofossil Trichophycus is widely reported from the Cambrian-Ordovician strata. However, only a few studies have been conducted to investigate its temporal and spatial occurrences, evolutionary paths, trace maker identy as well as its ecological features. Here, we report Trichophycus from the Lower-Middle Ordovician Meitan Formation of Renhuai area, Guizhou Province for the first time. These fossils consist of relatively wide, straight to curved, U-shaped burrow segments that are arranged in a protrusive mode. The lower and lateral surfaces of the burrows are characterized by sets of longitudinally arranged, parallel to sub-parallel striae. The burrow lacks lining and the infill shows retrusive spreite structures. These diagnostic characteristics allow an assignation to T. venosus Miller, 1879, which is interpreted as a dwelling/feeding structure constructed by a colony of unknown arthropods, while the trace maker of reported Trichophycus elsewhere may come from various groups, representing behavioral convergence. Trichophycus venosus is a member of the Glossifungites ichnofacies, possibly indicating an initial induration of the sea floor or a short-lived sedimentary hiatus. The ichnofossil Trichophycus may serve as a reliable indicator of firmground in shallow-marine settings. The geological distribution of Trichophycus, a pineer ichnogenus, suggests a diachronic infaunalization in shelf settings between different blocks. Occurrence of Trichophycus in the Meitan Formation represents colonization of the shelf substrate during the Great Ordovician Biodiversification Event on the Yangtze platform, South China.
    2022,61(4):615-627, DOI: 10.19800/j.cnki.aps.2021075
    Abstract:
    The Fengcheng Formation in the Mahu sag in northwestern Junggar Basin, Xinjiang, was deposited in an alkaline saline lake and contains large volumes of high-quality source rocks. PetroChina Xinjiang Oilfield Company conducted the Maye-1 borehole project and collected the entire sequence of the Fengcheng Formation in the Mahu sag to evaluate and explore the oil and gas potential in this area. In order to better constrain the age of the Fengcheng Formation, a palynostratigraphic project has been conducted since 2019. A total of fifty palynological samples, mainly of shale, claystone and siltstone, were collected from the Maye-1 core. All samples were cleaned, crushed, weighed (30-50 g for each sample), and macerated following the standard HCl-HF-HCl method. The organic residues were sieved through 180 and 10 μm meshes, respectively. The residues were then mounted on microscope slides using glycerin jelly. Palynomorphs were observed and photographed using a LEICA DM 2500 microscope equipped with a D800E camera. However, a considerable number of palynomorphs are not well preserved, usually with various sizes of secondary cavities or perforations. All slides are stored in the PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang, China. Positions of the spores and pollen illustrated in the text figures are located using an England Finder Slide. Based on systematic palynological identification and statistics, a new fossil palynological assemblage, Protohaploxypinus perfectus-Lunatisporites tersus (PT) assemblage, is established for the Fengcheng Formation. Twenty-nine species in twenty genera of spores and pollen were recognized in the PT Assemblage from fifty macerated samples. In the PT assemblage, the Disaccites striatiti pollen is dominant, while the fern spores are relatively rare. The comparison of the dispersed and in-situ spores and pollen associated with their reliable parent plants shows that the palynoflora consists of dominant species of Peltaspermales and species of Coniferales as the second major component. The PT assemblage is correlatable with the Crustaesporites–Protohaploxypinus–Hamiapollenites assemblage from the upper part of the Tashenkula Formation to the Wulabo Formation at the southern margin of the Junggar basin due to the high portion of the Disaccites striatiti pollen in the palynoflora and the crucial co-occurring species, including Gardenasporites bilabiatus, Triangulisaccites boleensis and Hamiapollenites saccatus. In addition, the PT Assemblage, mainly consisting of the Disaccites striatiti pollen (> 70%), differs from the Bashkirian Calamospora breviradiata–Lunatisporites tersus assemblage from the age-constrained Jiamuhe Formation in the nearby Zhongguai uplift. The latter assemblage bears a slightly less Disaccites striatiti pollen (ca. 60%) and an equal amount of Calamospora spores (ca. 40%), indicating that the PT assemblage is reliably dated as post-Bashkirian. Based on the precise U-Pb zircon dates from two tuff layers (304.9 ± 0.69 Ma and 299.9 ± 0.64 Ma) in the lower part and a tuff bed (296.9 ± 0.8 Ma) in the upper part of the Fengcheng Formation in the Mahu sag, the age of Fengcheng Formation is constrained to the Kasimovian–Asselian. In summary, careful palynological comparisons and precise geochronological data suggest that the PT assemblage from the Fengcheng Formation of the Maye-1 borehole was likely deposited from the Kasimovian to the Asselian age. Moreover, the age of the entire Fengcheng Formation in the Mahu sag should be younger than the Bashkirian, and the upper part of the Fengcheng Formation may contain some Asselin sediments. Abundant Disaccites striatiti pollen and the intriguing emergence of the cold-water Gadus in the shales and the warm-phase authigenic alkali minerals of eitelite and shortite from the interbedded saline layers indicate that the rhythmic sedimentary strata of the Fengcheng Formation in the Mahu sag were probably formed in paleoenvironments with frequent fluctuations of cold-dry and warm-dry paleoclimate conditions.
    2022,61(4):628-642, DOI: 10.19800/j.cnki.aps.2021072
    Abstract:
    The Late Permian Xiacangfanggou Group in Taoshuyuan area of Turpan Basin, Xinjiang consists of the Quanzijie, Wutonggou and Guodikeng formations in ascending order. The sedimentary sequence represents continuous fluvial-lacustrine siliciclastic deposits with abundant animal and plant fossils. The gastropod specimens described in this paper are found from the bioclastic limestone layers and limestone concretions in the lower and middle parts of the Wutonggou Formation at the Taodonggou section. These gastropod fossils collected from two horizons are assigned to six species, four genera belonging to two families. These species are Xinjiangospira rotundata, Xinjiangospira habita sp. nov., Hydrobia turpanensis, Hydrobia orientalis sp. nov., Pseudamnicola taodonggouensis sp. nov. and Valvata complanusa sp. nov. Other associated fossils are bivalves, phyllopods, ostracods, vertebrates and plants. The bivalves are dominated by Palaeanodonta, Palaeomutela and Anthraconauta. The Late Permian gastropod fauna from the Wutonggou Formation is composed of freshwater Hydrobiidae and Valvatidae. Characterized by well-preserved speci mens in large quantity, this fauna represents the most abundant Paleozoic freshwater gastropod fauna known so far. This fauna shows similarity to those from the Xiaolongkou Formation (= Guodikeng Formation) from the Dalongkou section, Junggar Basin, and the Upper Permian (Karu System) in southern Rhodesia, Africa.
    2022,61(4):643-653, DOI: 10.19800/j.cnki.aps.2021064
    Abstract:
    The anatomy of the forefins of Mixosauridae, including ontogenetic and intraspecific variations, remains poorly known due to the lack of well-preserved materials except for Mixosaurus cornalianus. Several specimens of Mixosaurus panxianensis in different sizes excavated from Panzhou City, Guizhou Province were studied. The result shows some ontogenetic variations in their ulnae, radialia, phalanges and pisiforms. Moreover, the development of the notches on the anterior margin of radius and the proximal margin of intermedium is variable within individuals of Mixosaurus panxianensis.
    2022,61(4):654-661, DOI: 10.19800/j.cnki.aps.2022011
    Abstract:
    The Jehol Biota is the best preserved Cretaceous terrestrial biota and one of the most important and exceptionally well-preserved lagerst?tten worldwide. According to the three-stage evolutionary theory of the Jehol Biota, this biota extended southward to the Qinling and Dabie mountains, including the western and southern regions of Henan Province, during the second stage. Earlier studies have documented Ephemeropsis trisetalis, a typical element of the Jehol Biota, from western Henan. In this paper, the larva fossils of Aeschnidiidae and Ephemeropsis trisetalis are first reported from the Nanzhao Formation in the Mashiping Basin, Nanzhao Country, western Henan Province. Aeschnidiid larvae were previously only recorded in the Yixian Formation and its equivalent strata. Aeschnidiid larvae belong to the characteristic element of the second stage of the Jehol Biota. The newly discovered insect fossils from western Henan confirm that the Jehol Biota had already reached this area during the second stage. This study further indicates that the age of the Nanzhao Formation is Early Cretaceous instead of Late Jurassic, and the Nanzhao Formation may be somewhat correlatable with the Yixian Formation in western Liaoning.
    2022,61(4):662-663, DOI: 10.19800/j.cnki.aps.2022028
    Abstract:
    In 1993, a new genus Liaoningia Yu and Dong, 1993 was proposed for Late Triassic non-marine bivalves of Liaoning Province, northeastern China. However, as early as 1970’s, Xing Yu-sheng and Liu Gui-zhi had created the genus name Liaoningia Xing and Liu, 1979 for the fossil specimens came from the Late Precambrian Nanguanling Formation at Wali, Paoya town of Fuxian County, Liaoning Province, northeastern China. According to Article 60. 3 of ICZN, we propose a new genus name, Liaoningoconcha nom. nov., to replace Liaoningia Yu and Dong, 1993, based on the same type species, Liaoningia opima Yu and Dong, 1993.
    2022,61(4):664-671, DOI: 10.19800/j.cnki.aps.2022035
    Abstract:
    Rugosa, Tabulata and Scleractinia are the three major fossil coral groups in the Phanerozoic. However, Chinese translations of their names are inconsistent. In this paper, following an introduction of the concepts of the three groups, the history of their Chinese names is reviewed, and their recommended usages are discussed. Rugosa ranges from the Middle Ordovician through the Permian, and is typified by serial septal insertion in four quadrants. This taxon was established by Milne-Edwards and Haime in 1850. Therefore, Rugosa has priority over Tetracorallia Haeckel, 1866, Tetracoralla Haeckel, 1870, and Tetraseptata Grabau, 1913, names subsequently introduced based on its distinctive mode of septal insertion. Chinese names of this fossil group first appeared in Japanese literature at the end of the nineteenth and the beginning of the twentieth century, with Tetracoralla being translated as “四射珊瑚” or “四放珊瑚”, and Rugosa as “褶襞珊瑚” or “皱皮珊瑚”. Other translations introduced later by Chinese authors include “皱纹珊瑚”, “皱壁珊瑚”, and “皱珊瑚”. Among all these translations, “四射珊瑚” and “皱纹珊瑚” are presently accepted and most widely used. But “皱纹珊瑚” is preferred herein due to the obsolescence of the terms Tetracorallia, Tetracoralla, and Tetraseptata, and their translation “四射珊瑚”. Tabulata was the other dominant coral group in the Paleozoic, ranging also from the Middle Ordovician to the end of the Permian. First proposed by Milne-Edwards and Haime in 1850, the name Tabulata takes priority over Aseptata Grabau, 1913. Its earliest Chinese translation was derived from the Japanese kanji name “床板珊瑚” at the end of the nineteenth century. Subsequent names translated by Chinese coral workers include “牀板珊瑚”, “横板珊瑚”, and “板珊瑚”. Among them, both “床板珊瑚” and “横板珊瑚” are still commonly used. However, we prefer the former due to its much longer history and more popularity. It is noteworthy that some authors used the name Aseptata and its translation “无射珊瑚”, and some adopted the concept of Tabulatomorpha Sokolov, 1971 and its translations of “床板珊瑚形珊瑚” and “床板珊瑚型珊瑚”. However, none of them has received much attention. Scleractinia, one of the major reef-building groups, first occurred in the Middle Triassic and persists to the present day. Forms now assigned to Scleractinia were initially part of Madreporaria Milne-Edwards and Haime, 1857. However, it was not until 1900 when Bourne introduced the name Scleractinia, and 1943 when Vaughan and Wells proposed its current concept. Two Chinese translations of the name Scleractinia have thus far been available, i.e., “石珊瑚” and “硬珊瑚”, with the former being more widely used and thus being recommended in this paper.
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    Abstract:
    The Ordovician in Yunkai area of western Guangdong Province mainly consists of sandstone, pelitic siltstone, silty mudstone and pebbly sandstone, and mudstone with intercalated carbonate rock lenses and conglomerates. The Ordovician includes the Lower Ordovician Luohong Formation and Luodong Formation, Middle Ordovician Dongchong Formation, and Upper Ordovician Lanweng Formation. Fossil bivalves, including the new taxa described in this paper, were collected from an about 2-meter-thick bed of gray to grayish yellow silty mudstone and pelitic siltstone of the upper part of the Dongchong Formation. The collection includes about one thousand bivalve specimens, which represent more than 22 species of 16 and several unnamed genera and may a possible new taxon. We report a group of unique bivalves including two new species of Yunannia gen. nov. of a new family Yunanniidae Zhang et Niu and a new superfamily Yunannioidea Zhang et Niu. This group demonstrate combined features normally attributed to different bivalve taxa. A small number of trilobites, including Nileus sp., Lonchobasilicus sp., Calymenesun tingi Sun, Calymenesun sp., Asaphopsis? sp., and brachiopods, including Paralenorthis sp., Aegira sp., Leptellina sp., Obolus? sp., Strophomena sp. and Nicolella sp., cooccur with the bivalves and indicate the Middle Ordovician age. SYSTEMATIC PALEONTOLOGYClass Bivalvia Linnaeus, 1758 in 1758–1759 Subclass Autobranchia Grobben, 1849 Infraclass Pteriomorphia Beurlen, 1944 Cohort Uncertain Superfamily Yunannioidea Zhang et Niu superfam. nov. Description Shell small, mytiliform, umbos anterior to terminal; strong inequilateral; buyssal sinus faint; the area beneath and anterior umbo edentulous; posterior to umbo a row of discrete chevron taxodont teeth; large anterior adductor muscle scar located in the umbonal angle and occupies the large and wide umbonal septum together with the anterior pedo-byssal retractors; posterior muscle scar unknown; external ligament, opisthodetic, submarginal; ligamental area narrow with 2-ranks of ligamental grooves and ridges, which are gently arched and extended continuously away from the dorsal margin; shell surface with faint comarginal growth lines. Remarks The Yunannioidea, a new superfamily of pteriomorphians is established based on the genus Yunannia proposed in the present paper. The Yunannia, the sole genus of the new superfamily Yunannioidea, is characterized by mytiliform outline, one posterior row of chevroned teeth, the large anterior adductor muscle scar located in the umbonal angle and inserted on the umbonal septum together with the anterior pedo-byssal retractor, and the arched two ranks of ligamental grooves and ridges which extend continuously away from dorsal margin. On the basis of features such as mytiliform, the musculature, and ligament, the Yunannioidea may be placed into the Cohort Mytilomorphi!. However, the genus Yunannia has only one row of posterior chevroned teeth. Together with its unusual hinge dentition, the new superfamily can be distinctly distinguished from other members of the same cohort. Meanwhile, features including the taxodont dentiotion and the two ranks of ligament indicate that Yunannia is likely in connection with Subcohort Ostreioni. Hence, the position of Yunannia at cohort level is undetermined. The genus Yunnania most possibly represents a new order of the infraclass Pteriomorphia. Family Yunannidae Zhang et Niu fam. nov. urn:lsid:zoobank.org:act:8A609836-4A82-4C6A-97B1-18168E761 891 Type genus Yunannia Zhang et Niu Yunannidae is the sole family of the new superfamily Yunannioidea. Distribution Middle Ordovician, Guangdong, China. Genus Yunannia Zhang et Niu gen. nov. urn:lsid:zoobank.org:act:B09DAFBA-A54D-4621-8FCD-07D8882 A6584 Type species Yunannia gankengensis Zhang et Niu gen. et sp. nov. Diagnosis Shell mytiliform, umbos anterior to terminal, with a row of posterior, discrete chevron taxodont teeth; anterior adductor muscle scar large and pedo-byssal retractor inserted on umbonal septum; ligament external and opisthodetic, extending continuously away from dorsal margin. Description The shell is small with height less than 21 mm. The shell shape is strongly inequilateral, mytiliform or narrow ovate with height longer than length. The umbos is anterior to terminal, projected and slightly incurved. Anterior lobe is absent. The dorsal-posterior margins are merged and widely arched. The anterior flange is thickened. The umbnal cavity is large and deep, separated by a lunate inner septum. The anterior adductor muscle scar is large and elliptical, located in the umbonalangle, and inserted on the umbanl septum together with the posteriorly extended pedo-byssal retractor. The growth line of anterior adductor muscle scar is present in one specimen. The anterior end of the anterior adductor scar is acuminate, likely marking the position of the pedal protractor but is obviously merged with the anterior adductor. The posterior adductor and posterior pedal retractor are unknown. The holotype, a left valve, bears about 20 teeth and sockets, while each half of a paratype bears about 8–15 teeth. The area anterior to and beneath umbo is edentulous. All teeth are discrete and chevroned with concavities towards distal end. The anterior two or three teeth are small and the rest become gradually larger posteriorly, achieving the maximum size about midway along the row of teeth. The teeth diminish gradually in size toward the posterior end of hinge plate. The ligament is external and opisthodetic, submarginal, sub-parallel to the gently arched dorsal-posterior shell margin. The ligamental area is narrow and extends posteriorly to about 3/4–4/5 height of shell, with one rather coarse ligamental ridge and two grooves above and below it (as the first-rank of ligament), while the weak and faint ligamental ridges and grooves (as the second-rank of ligament) within the first-rank ligamental grooves and ridge. Because of the number of first-rank ligamental groove-ridge couplets, it is likely the preduplivincular ligament. However, if the second-rank of ligament is also considered, the total number of ligamnental groove-rige couplets is more than two or three. Hence, it is likely the duplivincular ligament, rather than the preduplivincular ligament. In addition, the arched shape of ligamental area is similar to the simple arched ligament. The holotype specimen shows faint growth lines on the inner surface of shell wall. Etymology Yunan, a geographic name of a county in Guangdong Province. Remarks This genus is the sole representative of Yunannioidea superfam. nov. It is characterized by features such as the mytiliform shell having a posterior row of chevroned teeth, and the arched two ranks of ligamental groove-ridge couplets extending continuously away from the dorsal margin. The large anterior adductor located in the umbonal angle and inserted on the umbanl septum together with anterior pedo-byssal retractor. In addition, the large and wide umbonal septum is another distinguishing feature of Yunannia. The new genus combines some main features normally attributed to different bivalve taxa. Its dentition of taxodont teeth is similar to the Paleotaxodonta. The new genus and Ambonychioidea of Pteriomorphia share some features, including the mytiliform shape, terminal umbos and byssal sinus. Both the new genus Yunannia and cyrtodontoids have the same characteristic of sub-umbonaledentulous area. The present new genus and Dreissenoidea of Heteroconcha have common characters such as the anterior muscle scar inserted on umbonal septum, the submarginal, long, extended arched ligament. With the combination of features listed above, the new genus clearly distinguishes itself from all other genera in those taxa. Age and distribution Middle Ordovician; Guangdong, China. Yunannia gankengensis Zhang et Niu gen. et sp. nov. urn:lsid:zoobank.org:act:67E7B718-0211-4EBB-ADA9-898045A3 8637 (Figs. 3–5) Materials 8 specimens of internal moulds including 5 left valves and 3 right valves. Holotype: No. Ng4032, Paratypes: Ng4033, Ng4030, Ng4031, Ng1041. Diagnosis Height/length(width) ratio less than 1.5; ventral part of shell expanded and swollen. Description The shell is small, mytiliform, strongly inequilateral with height less than 20 mm. The height is longer than the length (width) with height/length(width) ratio less than 1.5. The umbos is terminal, projected and slightly incurved. The anterior lobe is absent. A faint byssal sinus is present at the upper part of anterior margin. The dorsal-posterior margins are merged and widely arched. A long and thickened anterior flange is present behind the anterior margin. A large umbnal cavity is separated by a lunate umbonal septum. The elliptical and large anterior adductor muscle scar is located in the umbonal angle, together with anterior pedo-byssal retractor, occupying the umbonal septum. The anterior adductor muscle scar being covered by growth line is showed in one paratype specimen (No. Ng1041). The anterior end of the anterior adductor scar is acuminate, which likely marks the position of the pedal protractor, but is obviously merged with the anterior adductor (as to otherwise indistinguishable). The posterior adductor and posterior pedal retractor are unknown. The area anterior to and beneath the umbo is edentulous. Posterior to the umbo there is a row of teeth consisting of 13–20 discrete and chevroned teeth with concavities towards the distal end. The anterior and posterior two or three teeth are small with the maximum size at the midway along the tooth row. The ligament is external and opisthodetic, submarginal, sub-parallel to the gently arched dorsal-posterior shell margin. The ligamenal area is narrow, extending posteriorly away from dorsal margin to about 4/5 height of the shell with one rather coarse ligamental ridge and two grooves laid above and below it (as the first rank of ligament), which are subdivided by the weak and faint (as the second rank) ligamental ridges and grooves. Because of the number of the first rank ligamental groove and ridge couplets, it is likely the preduplivincular ligament. However, if the second-rankof ligament is also considered, the total number of ligamnental groove-rige couplets is more than 2–3. Hence, it is likely the duplivincular ligament, rather than the preduplivincular ligament. Faint growth lines are present on the shell surface. Measurement Holotype: No. Ng4032: height 17.5 mm, length 13, H/L = 1.35. Etymology Gankeng, a geographic name of Guangdong. Comparison The present new species evidently differs from Yunannia yunkaiensis gen. et sp. nov. in having mytiliform shape, shell becoming gradually wider towards ventral side, with the maximum width near the ventral part of the shell, and a height/length ration less than 1.5. The latter species has a narrow and narrow ovate shape and a height/length ration about 2. Occurrence Gankeng Village, Yunan County, Guangdong Province; Dongchong Formation, Middle Ordovician. Yunannia yunkaiensis Zhang et Niu gen. et sp. nov. urn:lsid:zoobank.org:act:BE7BF3A3-3F07-4049-88F3-2EE989D4 E914 (Fig. 6) Materials 3 internal moulds of left valve. Holotype: No. Ng4035, Paratypes: Ng074, Ng4034. Diagnosis Shape narrow ovate and H/L ratio about 2.0. Description The shell is small, narrow ovate, strongly in-equilateral, 16.5–21 mm high. The height is much longer than the length with a H/L ratio of 2.0. The umbos is projected and slightly incurved. The anterior lobe is absent. The dorsal-posterior margins are merged and gently arched. The thickened anterior flange is relatively narrow. The umbonal cavity is separated by lunate, relatively narrow umbonal septum. The large and elliptical anterior adductor muscle scar is located in the umbonal angle, and together with the pedo-byssal retractor, inserted on umbanl septum. The anterior end of the anterior adductor scar is deeply inserted and becomes shallow poster-ventrally. The posterior adductor and posterior pedal retractor are unknown. The area anterior to and beneath umbo is edentulous with a posterior row of hinge tooth consisting of more than 8 to 13 discrete and chevroned teeth with concavities towards the distal end. The ligament is external and epithetic, submarginal. The ligamental area is narrow, sub-parallel to the gently arched dorsal-posterior shell margin, extending posteriorly away from dorsal margin to about 3/4 height of shell, and with one rather coarse ligamental ridge and two grooves above and below it (as the first rank of ligament). The four weak and faint ligamental groove-ridge couplets (as the second rank of ligament) extend about 5 mm in length in the dorsal side of the groove of the first rank ligament. Surface ornaments of the shell are unknown. Measurement Holotype: No. Ng4035; height 21 mm, length 10 mm, ratio H/L = 2.0. Etymology Yunkai, a regional geographic name in Guangdong Province. Comparison The present new species is distinguished from the genotype, Yunannia gankenensis (gen. et sp. nov) by the narrow ovate shape with a H/L ratio of 2, and the slightly incurved umbo. In contrast to the latter species’ mytiliform shape and a H/L ratio less than 1.5. On the respect of shell shape, the present species is more or less similar to Mytilarca chenmungensis (Conrad) (Pojeta, 1966, pl. 37, figs. 8–18; pl. 38, figs. 1–5, 10), but it differs from the latter species by having a subumbonal edentulous area, a posterior row of taxodont teeth, a large anterior adductor muscle scar, and large anterior pedo-byssal retractors laid on unmbonal septum. Occurrence Gankeng Village, Yunan County, Guangdong Province, Dongchong Formation, Middle Ordovician.
    Abstract:
    Populus L. is an ecologically important tree genus in the Northern Hemisphere temperate forest. In this paper we summarize the Populus fossil records from the Paleogene and Neogene of the Tibetan Plateau with updated stratigraphic and chronological data. Fossil evidence shows that Populus first occurred in the plateau in the latest Eocene. The genus is well-documented in the southern and northern Tibetan Plateau in the Oligocene and Miocene, but lacking in the central plateau. Most of the fossil floras in the Tibetan Plateau containing Populus are temperate, deciduous and broadleaved, riparian vegetation, further confirming that the genus had favored a temperate and riparian environment in their early evolutionary history. Besides, the high diversity and prominent dominance of Populus in early Oligocene flora in the northern Tibetan Plateau suggests this region had played an important role in the early diversification stage of Populus.
    Abstract:
    The journey to understand the Cambrian explosion started with Creation, was subsequently succeeded by Darwinism, and became increasingly impacted by the theory of explosive evolution. The Cambrian explosion by nature is an explosion of animal body plans alongside episodic biomineralization, pulsed change of generic diversity, body size variation, and increase of ecosystem complexity. It is a polythetic event in natural history and manifested in many aspects. No simple, single cause can explain the entire phenomenon. Intrinsic and extrinsic causes were extensively discussed but they are merely prerequi-sites for the Cambrian explosion. Without the molecular evolution, there could be no Cambrian explosion. However, the de-velopmental system alone is insufficient to explain Cambrian explosion. Time-equivalent environmental changes were often considered as extrinsic causes, but the time coincidence is also insufficient to establish causality. Like any other evolutionary event, it is the ecology that makes the Cambrian explosion possible though ecological processes failed to cause a burst of new body plans in the subsequent evolutionary radiations. While the Cambrian explosion did take place under circumstances when the world oceans became habitable for various forms of animals, the developmental Gene Regulatory Networks (GRNs) were sufficiently complex for constructing complex forms, and resource supply was less restricted. It seems that opportunities were in every corner! Early metazoans shared seafloors with vendobionts for the last 20 million years of the Ediacaran, although their ecological relationships are less known. Metazoans followed the path of evolving organs and sys-tems, developing orderly repetition of body parts, and attempting possibilities, which enable the evolution of morphological, physiological, ecological variations and complexity. While vendobionts kept their less differentiated body designs, tis-sue-grade organization, and probably osmotic physiology. Consequently, Ediacarans died off at the end of their era for un-known reasons. Thereafter metazoans rapidly diversified and generated numbers of phylum-rank stem or crown lineages with different fates. The Cambrian explosion ultimately resulted in the critical transition from microbially-dominated ecosys-tems in the Precambrian to metazoan-dominated ecosystems in the Phanerozoic. However, the temporospatial pattern of eco-systems during the Cambrian explosion is poorly understood, largely because our current knowledge is biased in metazoan evolution and redox conditions, and thus insufficient to reconstruct an ecosystem that is an integrative entirety of biotic and abiotic components. Therefore, we proposed a facies-dependent integrative approach as a working hypothesis toward a more comprehensive understanding of ecosystem evolution during the Cambrian explosion.
    Abstract:
    In accordance with the cranidia structures, the method of “Q-mode cluster analysis” used in the present paper for a taxonomic study of 18 species of the genus Mufushania, that was established or adopted by Lin Tian-rui (1965), Li Shan-ji (1978),Zhang Wen-tang et al. (1980), Sun Zhen-hua (1982), Zhou Zhi-qiang et al. (1982), Guo Hong-jun et al. (1996), Yuan Jin-liang and Li Yue (1999), Peng Shan-chi et al. (2001), Yuan Jin-liang et al. (2002). The statistical measurement of similarity is incremental sum of error squares (ΔE). The use of the variability by the author is the eight quantitative ratio values (see table 1). The resemblance relation matrices of all specimens are formed through calculation of the increments of sum of error squares between those specimens (see table 2). These data show that M. shalangensis Zhang and Zhou in Zhang et al. 1980(5), M. angustilimbata Zhang and Zhou in Zhang et al.,1980 (7) and M. kailiensis (Yuan in Yuan et al., 2002) (13) species should not be a member of the Mufushania, not belonging to species of Mufushania. Finally, through the application of combined cluster analysis with traditional qualitative analysis in the study of fifteen species of Mufushania trilobites in this paper, of which M. changi Lin, 1965 (2) is regarded as a junior synonym of the type species (1) and M. zhanjiaxiangensis Sun, 1982 (10) is regarded as a junior synonym of M. ezhongensis Sun, 1982 (9), too, the other thirteen species of Mufushania in the opinion on lumping and transferring the studied species is proposed (see table 3).
    Abstract:
    The value of the discoveries of Hamipterus tianshanensis and their 3D eggs fossils?are of?great importance.?These fossils preserved in Beijing for several years, the surrounding rocks have been powdering and flaking, which seriously endanger the safety to fossils. This paper intends to use XRF and other methods to detect surrounding rock to explore its corrosion mechanism. The analysis shows that the surrounding rock of fossils is composed of sandstone with boulder clay, which contains some clay minerals such as montmorillonite. The?sandstone?with?calcareous?and?salt?cementation contains large amounts of soluble ions such as Cl-, NO3-, Na+ and Mg2+. The mechanism of the deterioration is as followed, when the humidity changes, the soluble salt also generates large crystal pressure, as well as the expansion of clay minerals produces huge pressing force, leading the surrounding rocks to powder and flake gradually. The?solution?of?salt?existing?as the cement results in the escape and?migration of?particles, which?is?an important reason for fossil deterioration.?Based on the above understanding, this paper also gives suggestions about the protection of fossils.
    Abstract:
    The Renyi Section is a newly discovered section in the vicinity of Renyi Town, Hezhou City of Guangxi, in which a continuous marine sedimentary succession of the Middle and Upper Devonian is well developed and out-cropped. The succession yields abundant benthic and pelagic fossils. This paper presents a preliminary research resulton the conodonts and brachiopods from the middle part of the Middle-Upper Devonian Baqi Formation (ca. 80 m thick) at this section. Ten species (or subspecies) of three genera of conodonts are recognized from the studied interval, including Polygnathus alatus, P. cf. collieri, P. cristatus, P. dubius, P. dengleri, P. dengleri sagitta, P. webbi, P. xylus, Klapperina disparalvea and Schmidtognathus wittekindti. Seventeen species of 16 genera of brachiopods are also reported herein, including Schizophoria sp., Gypidula sp., productoid gen. et sp. indet., Leiorhynchus kwangsiensis, Coeloterorhynchus sp., Hypothyridina sp., Uncinulus? sp., Fitzroyella sp., “Ypsilorhychus” subellipticus, Desquamatia sp., Spinatrypina douvillii, Spinatrypina sp., Emanuella sp., Mucrospirifer sp., Undispiriferoides tianqipuensis, Cryptonella? sp. and Oligothyrina? sp. According to the distribution of the conodonts, three conodont zones (S. hermanni, P. cristatus and K. disparilis zones) have been recognized from the studied interval, suggesting an age of late Givetian of the Middle Devonian. The brachiopods were mainly collected from two fossiliferous layers near the base and top of the studied interval, representing two different brachiopod assemblages. The brachiopod fauna from the lower fossiliferous layer (ca. 20 cm thick, S. hermanni Zone) is relatively monotonous in composition, mainly consisting of L. kwangsiensis. This finding verifies the Middle Devonian occurrence of the genus Leiorhynchus in South China. The upper fossiliferous layer (ca. 3 m, upper K. disparilis subzone) yields a diverse brachiopod fauna, including at least 15 genera and displaying the highest diversity of brachiopods ever recorded in a single fossiliferous bed from the upper Givetian of South China.
    Abstract:
    This study describes the Guadalupian (Middle Permian) fusulines from the northern Zhabuye area in the Lhasa Block and discusses their palaeobiogeography. In total, the fusuline fauna comprises 6 genera and 16 species, including Yangchienia tobleri Thompson, Yangchienia haydeni Thompson, Chusenella brevipola (Chen), C. schwagerinaeformis Sheng, C. cf. brevis (Chen), C. sp., Nankinella rarivoluta Wang, Sheng and Zhang, N. complanata Wang, Sheng and Zhang, Kahlerina tenuitheca Wang, Sheng and Zhang, K. pachytheca Kochansky-Devidé and Ramov?, Verbeekina americana Thompson, Wheeler and Danner, V. tenuispira Sheng, Neoschwagerina cheni Sheng, N. colaniae Ozawa, N. craticulifera (Schwager) and N. brevis Thompson, Wheeler and Danner. This fauna suggests a Wordian age, as evidenced by the presence of Kahlerina and the thick spirotheca and less-developed secondary transverse septula in Neoschwagerina species. The fauna from the Zhabuye area is correlatable with the contemporaneous faunas from other regions in the Lhasa Block including the Shiquanhe area, the Xiadong area in Tsochen County, Xainza County and Lhunzhub County. The synchronous appearances of Guadalupian warm-water fusuline faunas in the whole Lhasa Block exhibit a pronounced difference in palaeobiogeography from the Tethys Himalaya region with persistent cold-water brachiopod faunas during the middle and late Permian. It is unlikely that the Lhasa Block and the Tethya Himalaya region adjoined together before the late Triassic. Therefore, it is considered that the Lhasa Block has been separated from the Gondwanaland by Wordian time.
    Abstract:
    Trilobites are common fossil animals in the Cambrian. The fossil record of their healed exoskeletons can provide important information on the competitive arms-race relationship between trilobite prey and their potential predators in the Cambrian ecosystem. The early Cambrian Chengjiang biota from South China, well known for its exceptional fossil preservation, allows us to study the ancient ecological interactions in marine communities during the Cambrian explosion. However, there is no record of healed trilobites so far known from the Chengjiang biota. The trilobite Eoredlichia intermedia Lu, 1940, an index fossil of the second trilobite biozone in eastern Yunnan of China, is one of the commonest arthropods in the deposits. Of more than 2 000 specimens of E. intermedia in our collection, two adult specimens are revealed with deformities in the lateral margin of cephalon, genal spine, and the pleural region. We suggest that such injuries were most likely caused by unknown predators. The scalloped fractures or cracks on these two adult individuals were marginally thickened and smoothed at the edges, indicating obvious signs of healing. If interpreted exactly, these fossils lend some supports for the view that the victim Eoredlichia intermedia was capable of repairing their fractured exoskeletons from sub-lethal attack by unknown predators. Therefore, this research presents the thus-far oldest fossil record of trilobites with injuries and the first report of the trilobite exoskeleton with healed injuries from the Chengjiang biota, signifying an existing escalating arms race between durophagous predators and prey since Cambrian Stage 3.
    [PDF 4.04 M] (1656)
    Abstract:
    The Jurassic and Cretaceous strata in northern China are mostly of terrestrial origin. It presents a difficulty in defining the Jurassic-Cretaceous (J/K) boundary. In the previous biostratigraphic work, the J/K boundary was referred to a higher posi-tion of much younger age, which caused a big controversy between local biostratigraphy and the international standard. Re-cently, large quantity measurements of isotopic ages reveal that the J/K boundary is possibly within the Tuchengzi Formation. The formation is a group of terrestrial reddish sedimentary deposits, and divided into 3 members. It is the type sequence of terrestrial Jurassic-Cretaceous transition in northern China. The stratigraphic age of the formation is in disagreement, owing to more-or-less limited preservation of fossils and a contradiction between biostratigraphic and isotopic data. Certain fossil groups have been found in scattered beds, dominated by conchostracans, ostracodes, dinosaurs, spore and pollen. Further-more, the pronounced provincialism of the terrestrial fauna and flora obstructs global correlation. Paleontologists have al-ready produced many publications after hard work, and they gave different stratigraphic divisions. A large amount of isotopic dating provides reliable data showing that the duration of the Tuchengzi Formation is from 156 Ma to 139 Ma, covering the late Jurassic to early Cretaceous period. The J/K boundary lies within this interval. Huge chronostratigraphic data challenge the traditional biostratigraphic results. The chronostratigraphic unit, otherwise, has to be indicated by a biotic boundary marker. Before a biostratigraphic division of high precision has been worked out, we attempt to make an option for the J/K boundary marker according to the data in our possession. After recognizing the fossil assemblages, the location of the J/K boundary is between the Jurassic conchostracan Pseudograpta-Monilestheria-Sinograpta (P-M-S) and ostracode Cetacel-lasubstriata-Mantelliana alta-Darwinula bapanxiaensis (C-M-D) assemblages, and Cretaceous conchostracan Yanshano-leptestheria-Pingquania-Lingyuanella (Y-P-L) and ostracode Djungarica yangshulingensis-Mantelliana reniform-is-Stenestroemia yangshulingensis (D-M-S) assemblages. It is also indicated by the first appearance of spore and pollen Ci-catricosisporites-Lygodioisporites-Jiaohepollis (C-L-J) Assemblage. Lithologically, the boundary is between the members 2 and 3 of the Tuchengzi Formation and of ~145 Ma in age. The Batuying sections in Beipiao are recommended as the type sequence of the formation. Based on the occurrence of the earliest Cretaceous fossil assemblages in the member 3, we pro-pose a “Batuying Stage” as the lowermost terrestrial chronostratigraphic unit of the Cretaceous in China. The duration of the stage is 145–139 Ma, correlating roughly to the international Berriasian Stage. The members 1–2 are referred to the upper-most “5th stage” which approximately corresponds to the Kimmeridgian–Tithonian stages of the Upper Jurassic. The present suggestion is only to provide a consultation for the terrestrial Cretaceous chronostratigraphic study.
    [PDF 2.29 M] (1583)
    Abstract:
    Amber, as an organic gem, is fossilized natural resin widely distributed around the world, especially Baltic region in Europe, Dominica-Mexico in Central America, and Myanmar in Asia. Insects are the most common inclusions in amber, while verte-brate inclusions are the rarest. However, compared to vertebrate fossils from sedimentary rocks, vertebrate inclusions trapped in amber pieces can provide additional information about the soft tissues, primitive death states, and living environment, as well as more visualized and refined 3D morphological information, all of which are important for studies in evolution, palae-oenvironmental restoration, palaeoecology and palaeoethology, which is more intuitive, stereoscopic and detailed than bone fossils. This paper reviews vertebrate inclusions from various amber biotae, including non-avian dinosaurs, aves, mammals, reptiles and amphibians, as well as their evolutionary implication, and also provides a framework of future researches.
    Abstract:
    Ostracods are described for the first time from the Late Ordovician in Nyalam, southern Xizang (Tibet), China. Thirty species belonging to sixteen genera are described and figured from the Jiaqu Formation in the Yalai Waterworks section. The ostracod fauna suggests a probable Sandbian-Katian Age for the Jiaqu Formation. The ecological assemblage of ostracods fauna belongs to the Eifelian Ecotype, which implies a nearshore depositional environment for the Jiaqu Formation. In the diverse ostracod fauna of the Jiaqu Formation, many cosmopolitan or provincial genera are shared in Himalaya, Tarim and South China, suggesting a close biogeographic relationship for the blocks.
    Abstract:
    Re-examination of the holotype specimen of the clam shrimp type species Loxomegaglypta wetlugiana Novojilov, 1958 us-ing a scanning electron microscope (SEM) has revealed details of carapace features with important taxonomic value, which have never been described hitherto. The new features include: growth bands in the middle and ventral part of the carapace are ornamented with circular, angular or elliptical sieve-like fine pits (15 to 25 μm in diameter), which are surrounded by vari-ously shaped, wide swellings. Puncta (4 to 6 μm in diameter) occur not only in the pits, but also on the surrounding swell-ings. This ornamentation pattern is different from the originally described angular reticulation, and thus the diagnosis of Loxomegaglypta is emended.
    Abstract:
    Up to now, little is known about the palaeovegetation of the most northeastern part of the great Qinghai-Xizang (Tibet) Plateau during the Neogene time. In this study, we report Miocene pollen and spore assemblages from the Maladun Formation at Hongtupo, a small mountain about 50 km southwest of Songpan County town, Sichuan Province. The palynoflora is characterized by rich presence of Ulmaceae, Betulaceae and abundant Pinaceae pollen with rare spores. Angiosperm pollen occupies 52.9%–84.4% of the total tally. Gymnosperm pollen form 13.8%–44.1% of total pollen and spores. Spores only amount to 1.9%–5.1% of the total assemblage. Other elements in the pollen flora include common Fagaceae (Quercus, Castanea), Salix, Juglandaceae (Juglans, Carya) and minor Liquidambar, Sporotrapoidites, Lonicera, Ephedra, Compositae (Asteraceae), Rosaceae, Leguminosae (Fabaceae), Polygonaceae, Ranunculaceae, Lythraceae etc. Such a pollen flora represents a mixed broadleaved and conifer forest. The pollen flora of the Hongtupo is of late Early Miocene to early Middle-Miocene age based on the correlation with the similar pollen assemblage from the Lengshuigou Formation of Weihe Basin which was dated by the associated vertebrate fossils. The palaeoclimate derived from the pollen flora should be of cold temperate to temperate with an annual temperature of about 8℃–13℃. The present pollen flora shows a much less warm appearance than those of the similar age pollen floras from northern and eastern China, which leads to a deduction of palaeoaltitude at the fossil locality of over 1000 m to about 2000 m above sea level. It is interesting that the pollen flora also contains some warm-loving elements such as Liquidambar and Juglandaceae pollen, which probably implies the Miocene Hongtupo area was neighbored by a low terrace or valley landscape.
    [PDF 3.84 M] (1457)
    Abstract:
    A new genus and species, Ayaimatum trilobatum gen. et sp. nov. Jiang and Szwedo, is described based on a planthopper preserved in mid-Cretaceous amber from Kachin State, northern Myanmar, and assigned to the Cretaceous planthopper fam-ily Mimarachnidae. A short overview of fossil record of the Mimarachnidae is given. The taxonomic diversity and morpho-logical disparity of this extinct group is briefly discussed.
    Abstract:
    This paper briefly summarizes the history of amber research in China and introduces the content of this special issue. The special issue includes 13 papers of 26 authors in 14 universities or institutes and covers some new progresses about plants, vertebrates, gastropods, and insects in mid-Cretaceous Kachin amber biota.
    Abstract:
    40 years ago, the 3rd National Congress and the 12th Annual Conference of the Palaeontological Society of China was held in Suzhou of Jiangsu Province. The Congress has historical significance in the Chinese palaeontological development. Since 1979 the Chinese palaeontological research entered a new developmental stage, with excellent achievements springing up in large numbers, and frequent academic exchanges occurring. In the following years, the activities of the Society were more active than ever before, significant increase in membership, the activities of society had regularized. The Chinese paleontologists have returned to the international community with frequent exchanges.
    [PDF 4.51 M] (1347)
    Abstract:
    The stonefly fauna in mid-Cretaceous Burmese amber is reviewed. A new fossil stonefly, Burperla decolorata gen. et sp. nov., is described and illustrated based on a well-preserved female specimen. This new taxon is characterized by the combi-nation of the following characters: long and pale body, long palps and antennae, RA almost reaching wing apex, subgenital plate broad and rounded with a posteromedial projection. These morphological characters distinguish it from other extant and extinct stoneflies of Perlidae.
    [PDF 1.66 M] (1323)
    Abstract:
    Thalattosaurs are one of the three major groups of top reptilian predators in the Triassic marine ecosystems, the study of which is a key to our understanding of biotic recovery from the Permo-Triassic mass extinction. Significant advancement has been achieved in the last decades in studying biodiversity and phylogeny of Thalattosaurs. However, the origin of Thalatto-saurs and the process forming the biogeographical pattern of Thalattosaurs largely remains an enigma. We review here the recent progress in the study of Thalattosaurs in terms of its origin, species diversity, phylogeny and biogeography. Our re-view shows that large gap exists in the research of Thalattosaurs. Future research should be focused on field work in the early part of the Triassic strata to search for more primitive Thalattosaurs. This is necessary to elucidate its origin. A first-hand systematic review of Thalattosaurs from SW China should be performed to clarify the true biodiversity of Thalat-tosaurs, which is also a basis for a comprehensive phylogenetic analysis of thalattosaurian relationships. Finally, the study of the physiology and paleoecology of Thalattosaurs via the investigation of long bone histology and microanatomy is of great significance in establishing the process forming the biogeographical pattern of Thalattosaurs.
    [PDF 2.86 M] (1272)
    Abstract:
    A new species, Stavba vrsanskyi sp. nov., is established and attributed to the family Liberiblattinidae on the basis of a blat-tarian specimen from mid-Cretaceous Burmese amber. The new specie differs from Stavba babkaeva Vr?anská and Vr?ansky, 2019 in the following characteristics: triangular head shape, R of forewing without secondary branches and less M. This new find provides novel biology diversity in Blattaria in mid-Cretaceous Burmese amber.
    [PDF 2.71 M] (1250)
    Abstract:
    Burmese amber contains one of the most diverse amber biotas all around the world. The geological age for Burmese amber is about 98.8 Ma, which was widely accepted as mid-Cretaceous. The Burmese amber biota provides an important window for us to seek the biodiversity and palaeoecology of the ancient world. Here, based on the study of stratigraphy and palaeobiolo-gy, palaeoenvironment and the deductions of the insect behavioral ecology proposed by numerous authors are comprehen-sively reviewed. These fields refer to co-evolution of insect and plant, predation, eusocial evidence, parasitism, courtship be-havior and structural coloration, provide us a more comprehensive summary of palaeoecology and insect behavioral ecology in Burmese amber.


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