The discovery of whole-plant fossil cycad from the Upper Triassic in western Liaoning and its significance

A recently discovered megafossil of whole plant cycad is briefly reported here. The specimen is collected from the Yangcaogou Formation （Upper Triassic） in Changheying, Beipiao, Liaoning. The whole plant is preserved intact on a sandstone slab, 89 cm long and 130 cm wide, including leaves up to 82 cm long and a male cone physically attached to the stem apex. Analysis on the morphology, arrangement and venation of leaf and pinna, male cone and its relationship with other parts indicates that the fossil is closely related to living Zamiaceae in Cycadales. This cycad fossil is hitherto most completely preserved cycad specimen including both vegetative and reproductive organs. Its discovery contributes much to our understanding of the morphology and evolution of cycads, palaeoclimate as well as palaeoenvironment.     

Discovery of fossil monocotyledons from Yixian Formation, western Liaoning

This is the first reports of a few fossil monocotyledons, includingLiaoxia chenii gen. et sp. nov. (belonging to Cyperaceae),Eragrosites changii gen. et sp. nov. (Gramineae) and a monocotyledonous leaf-shoot, obtained from the Late Jurassic Yixian Formation of western Liaoning Province, NE China. These fossils are the oldest known angiosperms in the world. It may be inferred that the earliest angiosperms probably appeared even earlier than the Late Jurassic.     

A new iguanodontid (Jinzhousaurus yangi gen. et sp. nov.) from the Yixian Formation of western Liaoning, China

A new iguanodontid,Jinzhousaurus yangi gen. et sp. nov., is erected based on the cranial and dental morphology of a specimen from the Yixian Formation of western Liaoning. Although a few primitive characteristics remain,Jinzhousaurus yangi display a number of characteristics similar to those seen in derived iguanodontids. Other interesting characteristics include the absence of antorbital fenestra and the frontal excluded from the participation in orbit, which are closer to the condition in hadrosaurids. The unusual combination of the characteristics provides important data for assessing morphological evolution toward hadrosaurs. The new discovery also represents the first reported large-sized dinosaur from Jehol fauna in western Liaoning, and increases the diversity of this famous fauna. Furthermore, the discovery of a derived iguanodontid from the Yixian Formation provides further evidence supporting a Cretaceous age of the Jehol fauna, which is consistent with an isotopic age.     

Discovery of a pterodactylid pterosaur from the Yixian Formation of western Liaoning, China

A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly equal length of metatarsals I–III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae:Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first non-controversial fossil record of Pterodactylidae in Asia.Haopterus is more derived thanPterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery ofHaopterus gracilis provides further evidence for the study of the origin and radiation of the Jehol Biota; it also sheds new light on the evolution and distribution of pterosaurs in the late Mesozoic.     

Sauropterygian from Triassic of Guizhou, China

A new sauropterygian,Anshunsaurus huangguoshuensis, is described on the basis of a well-preserved skull from the Late Triassic Wayao Member of Falang Formation, Guizhou Province, southwestern China. It is ascribed to Eusauroptetrygia because it possesses the following characters: the rostrum is mainly composed by the premaxillae; the nasals are small, paired and separated from one another by the premaxillae; the external nares are close to the orbits; and the frontals are fused.Anshunsaurus differs from other Triassic sauropterygians in its large size, long rostrum and the supratemporal fenestrae slightly smaller than orbits. It is further considered to be closely related toPistosaurus on the basis of the nasals contact with the prefrontals; large pineal foramen, lain in the anterior part of the parietal table; the squamosals not in contact posterior to the supratemporal fenestra. The discovery ofAnshunsaurus with the ichthyosaurs in the same locality indicates a new assemblage of Triassic marine tetrapods in China.     

云南省东部罗平地区晚三叠世卡尼期菊石生物地层

描述了产于云南省东部罗平地区牛补歹剖面上三叠统“法郎组”瓦窑段菊石带Trachyceras multitube- rculatum带之上地层中的菊石4属8种(含1比较种和3未定种), 其中Trachyceras aonoides, Simonyceras simonyi系国内首次报道。 依据各物种组合特征及其地层分布情况, 自下而上识别出菊石Trachyceras aonoides带和Austrotrachyceras triadicum带, 时代上大致对应晚三叠世早卡尼期的中晚期。     

辽西冀北晚中生代的化石蜥蜴类(爬行纲:有鳞目)

个蜥矢部部龙趾大具有辽西冀北晚中生代已记录的蜥蜴类化石共4属5种,及2个未命名属种。这些化石自下而上可划分4蜴类化石带：中侏罗世杨氏矢部龙带(Yabeinosaurus youngi Zone)、早白垩世早期长趾大凌河蜥-细小龙组合带(Dalinghosaurus longidigitus-Yabeinosaurus tenuis Assemblage Zone)、早白垩世早期细小矢带(Yabeinosaurus tenuis Zone)及早白垩世晚期炭德氏蜥带(Teilhardosaurus canbonarius Zone)凌河蜥-细小矢部龙组合带中的蜥蜴类属种最为丰富且分布较广,为研究早期蜥蜴类的地理地史分重要价值。布长等     

A new family of primitive mammal from the Mesozoic of western Liaoning, China

A fairly well-preserved specimen of a new primitive mammal, Repenomamus robustus gen. et sp. nov., has been described from the Yixian Formation (Lower Cretaceous), western Liaoning, China. This animal has several derived characteristics, such as well-developed den-tary/squamosal articulation, reduced number of tooth, differentiation of premolars and molars in postcanine teeth, presence of a dorsal process of the premaxilla that is not in contact with the nasal, closed medial wall of the orbit, and presence of fingerlike promontorium on the petrosal. It also retains some primitive reptile-like features. It is the most primitive taxon among the three mammals known from the Jehol Biota, and also represents the largest mammal of Mesozoic age over the world.     

New fossil ommatid (Coleoptera: Archostemata: Ommatidae) from Jehol Biota of western Liaoning, China

In this paper one new genus and one new species of fossil ommatid, Odontomma trachylaena gen. et sp. nov., is described and illustrated from the Late Jurassic or Early Cretaceous Yixian Formation of western Liaoning, China. Based on wide epipleural space of elytron with several rows of cells, the new taxa is attributed to tribe Brochocoleini of Ommatidae and compared with genus Brochocoleus. Due to the fact that most other Chinese Mesozoic ommatids are not complete, the complete preservation of the new specimens reported here enabled us to determine the characteristics of the body of these ancient ommatid. Moreover, based on the well-preserved individual of this new genus, we may suppose the affinities of the new species with extant and extinct groups.     

Two new ornithurine birds from the Early Cretaceous of western Liaoning, China

We describe two new ornithurine birds from the Early Cretaceous Jiufotang Formation of western Liaoning, northeast China: Yanornis martini gen. et sp. nov. and Yixianornis grabaui gen. et sp. nov. They represent the best fossil record of ornithurine birds known from the Early Cretaceous. They are more advanced than the most primitive ornithurine Liaoningornis, and are more similar to the other two Chinese Early Cretaceous ornithurines Chaoyangia and Songlingornis. Compared with Confuciusornis, Liaoxiornis and Eoenantiornis from the same age, the two new birds show remarkable advanced characteristics and suggest the presence of powerful flight capability like modern birds. Compared with Yixianornis and Chaoyangia, Yanornis is larger, with a more elongated skull and relatively long wings. The new discoveries indicate that by the Early Cretaceous both enantiornithine and ornithurine birds had already radiated significantly. The flight structures of Yanornis and Yixianornis are hardly distinguishable from those of modern birds; however, both retain a few primitive traits such as teeth on the jaws, wing claws and pubic symphysis, which exclude them from being the most recent ancestor of all extant birds.     

A new cyamodontoid placodont from Triassic of Guizhou, China

A new cyamodontoid placodont is named (Psephochelys polyosteoderma gen. et. sp. nov.) and described based on a three-dimensionally preserved specimen. The material comes from the Wayao Member of the Falang Formation (Carnian, Late Triassic) in Guizhou Province, southwestern China. The skull of Psephochelys shows a unique combination of characteristics observed in Psephoderma and Placochelys, and the carapace is diagnostic of a new taxon as well. The ventral dermal armor of Psephochelys differs from all other known cyamodontoids in that it comprises irregular marginal osteoderms in loose contact with each other, and gastralia between them. The cranial suture pattern is in part difficult to analyze due to apparent co-ossification of elements, or poor delimitation of sutures.This affects primarily the demarcation of the nasal from the prefrontal, and the relation between the anterior part of the parietal, posterior ends of the frontals, and postfrontals.However, the postfrontal appears to enter the anteromedial margin of the upper temporal fenestra, a characteristic otherwise known from Placodus, but not from other cyamodontoids. However, given the difficulties of interpretation of this skull, additional material is required to unequivocally assess some details of the pattern of cranial sutures.     

Histological observation of some primitive euconodonts of Late Cambrian from Liaoning

The histology of some euconodonts of Late Cambrian from Benxi and Fuxian County, Liaoning Province is studied by the oil-immersion technique. The histological characteristics of six primitive species of euconodonts - Proconodontus muelleri， Proconodontus tenuiserratus， Granatodontus ani， Rotundoconus tricarinatus， Teridontus nakamurai and Cordylodus proavus are described in detail. Tubular dentine and atubular (parallel- and wavy-lamellar) dentine are found in the basal bodies of the primitive euconodonts Proconodontus tenuiserratus and Proconodontus muelleri, respectively. The tubular dentine and spherulitic dentine are also recognized from the basal bodies of Granatodontus ani and Rotundoconus tricarinatus. Since the histological characteristics of the studied six species of euconodonts belonging to Proconodontus lineage and Teridontus lineage Sensu Miller (Univ Kansas Paleontol Contr, 1980, 99: 1?39) seems to be almost the same, euconodonts are proposed as possibly monophyletic herein.     

华北地块沁水盆地下三叠统刘家沟组古地磁倾角浅化研究

对华北地块沁水盆地下三叠统刘家沟组红层样品进行系统的岩石磁学、磁组构和古地磁学研究, 并用E/I (elongation/inclination)方法对其进行磁倾角浅化的识别与校正, 获得刘家沟组红层磁倾角浅化因子f = 0.6。岩石磁学结果显示, 刘家沟组红层的主要载磁矿物是赤铁矿及磁铁矿, 其磁组构具有典型的静水沉积特征。经地层校正后, 15个采样点特征剩磁分量的平均方向为D_s=318.8°, I_s=30.9°(α₉₅= 6.9°), 对应的古地磁极为49.3°N, 5.5°E (A₉₅=6.7°), 磁倾角浅化校正后的古地磁极为53.5°N, 18.0°E。对包括本文数据在内的高质量的华北早三叠世古地磁极数据(Q≥4)进行平均, 得到校正前的古地磁极为55.3°N, 357.1°E (A₉₅=5.5°), 校正后的古地磁极为60.8°N, 13.4°E (A₉₅=5.8°)。经过古地磁倾角浅化校正, 华北地块早三叠世的古纬度有约10°的明显提高, 指示其东部早三叠世时与华南地块之间可能存在一定的纬度差, 但是该纬度差很可能并不代表华北地块东部早三叠世时与华南地块尚未对接, 而是指示华南地块下三叠统灰岩同样存在显著的磁倾角浅化现象。     

A new eutriconodont mammal from the early Cretaceous Jehol Biota of Liaoning,China

A new genus and species of eutriconodont mammal, Chaoyangodens lii gen. et sp. nov., from the Dawangzhangzi bed of Yixian Formation, Lingyuan, Lia- oning, is reported. The new species has a tooth formula I5- C1-P1-M3/i4-cl-pl-m4, unique among eutriconodonts in having only one premolar in lower and upper jaws, respectively, and a distinctive diastema between the canine and the premolar. Its simple incisors and reduced premolars show a mosaic combination of primitive and derived fea- tures. This new taxon adds to the diverse group of Jehol eutriconodonts. Among the known species from at least three horizons, there seems no evolutionary trend in mor- phology that is recognizable, except for that larger species are all from the Lujiatun bed of the Yixian Fro. A thorough and systematic analysis involving all the Jehol eu- triconodonts is needed to understand their phylogenetic relationships.     

A new pterosaur (Pterodactyloidea,Tapejaridae) from the Early Cretaceous Jiufotang Formation of western Liaoning,China and its implications for biostratigraphy

In this article we describe a new and exceptionally weel-preserved pterodactyloid pterosaur,Sinopterus dong gen.et sp.nov.from the Jiufotang Formation in western Liaoning Province of northeast China,The new species is referred to the family Tapejaridae,representing its first record outside Brazil.It also represents the earliest occurrence as well as the most complete sketeton of the famil.Some revisions are made about the family according to the mophological observations of the postcranial bones of Sinopterus.Two pterosaur assemblages appear to have existed in the Jehol Group,represented by the lower Yixian Formation and upper Jiufotang Formation,respectively,The lower pterosaur assemblage shows some resembalance to that of the Late Jurassic in Solnhofen (Tithonian)by sharing members of the Pterodactylidae and Anurognathidae.The upper one shows more resemblance to that to the Early Cretaceous Santana Formation (Aptian/Albian) by comprising only pterodactyloids such as the Tapejaridae,The age of the Yixian Formation is younger than that of the Solnhofen lihographic limestone ,and the age of the Jiufotang Formation (Aptian )is slightly older than the Santana Formation.     

赣东北晚三叠世古地理演化及聚煤作用

赣东北晚三叠世含煤岩系形成于受武夷,怀玉和江南山地所限制的咸水、半咸水陆缘近海湖沉积环境。古地理演化、沉积环境明显控制含煤岩系沉积特征及聚煤作用。     

四川盆地西部上三叠统须家河组物质来源：碎屑锆石LA-ICP-MS U-Pb年龄研究

对四川盆地西部晚三叠世须三期须家河组碎屑长石石英砂岩和须四期砂岩中碎屑锆石进行了U-Pb定年。分析研究表明:1川西西部都江堰地区沉积物样品具四个主要年龄峰分别为245 Ma、460 Ma、773 Ma和1 836 Ma;川西北部广元地区样品具四个主要年龄峰分别为245 Ma、452 Ma、834 Ma和1 850 Ma;2结合碎屑锆石U-Pb测年特征,表明川西盆地北段广元地区和中段都江堰地区须家河组上部和下部年代学以及地球化学信息一致,主要显示吕梁期(峰值1 836 Ma、1 950 Ma和1 850 Ma),晋宁末期(峰值为865 Ma和834 Ma),加里东期(峰值为460 Ma和452 Ma)和海西-印支期年龄峰(峰值为245Ma),反映两个地区具有相似物源;3结合碎屑锆石U-Pb年龄与周源造山带对比分析,海西-印支期碎屑物质来源于秦岭造山带;加里东期是秦岭造山带的主要造山阶段,秦岭造山带为该阶段提供物源;晋宁末期是扬子克拉通岩浆活动最活跃时期,扬子克拉通为该阶段碎屑物质主要源区;吕梁期碎屑锆石,主要来自其北缘的华北克拉通。