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1.
<正>Aphids are marked by their high polymorphism,but species reported from the Early Cretaceous are known only from alate morphs.The discovery of an apterous adult morph in Lebanese amber and a larva of the same species are very important for the understanding of both the morphological and biological evolution of this insect group at the very early stage of development.Gondvanoaphis estephani new subfamily,new genus and species of the recent aphids family Thelaxidae is described.The characters of the new genus in respect to other genera placed in Thelaxidae are reviewed.The palaeoecological and palaeogeographical data concerning Gondvanoaphis new genus are also discussed.  相似文献   

2.
Changxingian ammonoids are well developed in South China, including 154 species, 33 genera and 11 families. They are mainly distributed in the southern and northern subprovinces of the South China province but are rare in the middle. According to the development of the ammonoid zone and lithologic characteristics, the two subprovinces are subdivided into six endemic areas. The above-mentioneddistribution is controlled by such factors as palaeogeographic environment and sedimentary facies.The evolution of Changxingian ammonoids of South China is characterized by distinct evolutionary stages, and the whole evolutionary history of ammonites consists of alternate episodes of"explosive" radiation, slow and steady evolution and mass extinction. The alternation of mass extinction and"explosive" radiation usually occur at the boundaries of stages(or substages)."Explosive" radiation refers to rapid proliferation of new species(or genera) within a very short geologically negligeable period of time. The origin of species can be well explained by the concept of punctuated equilibria--a new concept of evolution. Mass extinction refers to rapid, large-scale demise of taxa within a very short period of time. The cause of such an extinction might be due to the inevitable replacement of the old forms by rapidly developing new ones and the environmental changes, in addition to the global sea-level changes, extraterrestrial impacts and geomagnetic reversal.  相似文献   

3.
A new specimen discovered from the Falang Formation in northeastern Yunnan represents the most complete skeleton of Triassic pistosauroids. The new specimen is referred to Yunguisaurus Cheng et al., 2006 on the basis of the skull features, such as the presence of a separated nasal entering the external naris, a large pineal foramen located at the frontal/parietal suture and an interpterygoid vacuity with a narrow anterior extension. The new specimen differs from the type species of Yunguisaurus liae Cheng et al., 2006 in some aspects. Most of these differences can be attributed to ontogenetic variations. The new specimen is provisionally considered as Yunguisaurus cf. liae although its relatively short snout of the skull and slenderer hyoid may not be explained ontogenetically. Whether or not the new specimen represents a different taxon has to wait for a detailed study of the whole skeleton.  相似文献   

4.
The rugosan fauna from the Guanyinqiao Bed （latest Ordovician, Hirnantian） of northern Guizhou, China is known to belong to the cold or cool-water type corals. The components of the fauna are solitary corals only, and corallite septa are generally strongly dilated, especially the streptelasmatid corals are dominant comprising 98% of the whole fauna. The Guanyinqiao Bed is rich in rugosans of 18 genera, which are streptelasnmtid Streptelasma （=Helicelasma）, Brachyelasma, Amplexobrachyelasma, Salvadorea, Grewingkia, Borelasma, CrassUasma, Leolasma, KenophyUum, UUernelasma, Paramplexoides, Siphonolasma, Pycnactoides, Dalmanophyllum, Bodophyllum, Axiphoria, Lambeophyllum and cystiphyllid Sinkiangolasma. Although this fauna was fairly abundant in a confined area （northern-northeastern Guizhou, southern Sichuan） during the Hirnantian age, the rugosan mass extinction （generic extinction rate 81%） happened at the end of the Hirnantian Stage. It is conduded that the mass extinction is related to the ending of maximum glaciation and ice cap melting in Gondwana in the southern hemisphere in the latest Hirnantian, resulting in rapid global sea-level rise in the earliest Silurian. In the Upper Yangtze Basin, the sea bottom environments were replaced by anoxic and warmer water during that time, so that the cool-water type rugosan became extinct. The present paper attempts to revise some already described rugose coral genera and species （He, 1978, 1985） and to supplement a few new forms from the Guanyinqiao Bed. Fourteen species of 12 genera are re-described and illustrated, of which one species- Grewingkia latifossulata is new. As a whole, the rugosan fauna of the Guanyinqiao Bed may be correlated with those contemporaneous of North Europe, Estonia and North America, indicating a dose biogeographic affinity to North Europe.  相似文献   

5.
<正>A new sauropod dinosaur,Liubangosaurus hei gen.et sp.nov.,is erected based on a specimen represented by five articulated middle-caudal dorsal vertebrae,which was discovered in the Lower Cretaceous Napai Formation of Guangxi Province,southern China.This new taxon is diagnosed by a unique combination of derived features:prezygapophysis closely contacts with parapophysis,with the prdl and prpl absent;presence of cavity on the dorsal surface of the diapophysis;neural spine very low,with its distal end level with that of diapophysis;distal end of the neural spine strongly expanded laterally to form a platform;marked fossa formed between the infradiapophyseal lamina and the parapophysis;broad,flat area of featureless bone on lateral surface of neural arch;vertically directed infradiapophyseal lamina expands or bifurcates ventrally to form a inverted "Y";highly positioned parapophyses large and tear-drop in shape.The discovery of this new taxon increases the diversity of sauropods in China during the Early Cretaceous.  相似文献   

6.
《地质学报》1940,20(2)
Previous studies of Archocyathina from the Gorge District of the Yangtze and other parts ofChina are briefly reviewed. Ninc species of Arch?ocyathina, belonging to four different genera andtwo families are described and illustrated, of which only two species are new. The presence ofCambrocyathus (="Archaeocyathus"). Archaeocyathus (="Spirocyathus"), Retecyathus andProtopharetra known from Siberia Sardinia and Australia is reported for the first time. Stratigraphicalposition and distribution of the Archaeocyathina beds in Hupch, Szechuan and Kwcichow are discussed.Special consideration is given to the so-called "Ichang limestone" of Cambrian age. The age of theArchaeocyathina beds in central China is referable to the Lower Cambrian.  相似文献   

7.
Based on the systematic study of two fossil skeleton specimens collected from the top of the third member of the marine Lower Triassic Jialingjiang Formation of Yuanan, Hubei Province, South China, a new Early Triassic primitive ichthyosaur Chaohusaurus zhangjiawanensis sp. nov. is reported and described. The beds yielding the type material are correlated with the Neospathodus homeri-N. triangularis Conodont zone. The new taxon is most similar to Chaohusaurus geishanensis Young and Dong, 1972 in the shape and configuration of the scapula, forefin, pelvic girdle and hindfin, presacral vertebral count and well-developed caudal peak, but distinguished from the latter by its larger size, the position of the pineal foramen in the centre of the parietal, the occurrence of a larger calcaneum in hindfin and the first sacral rib with distal expansion. The new species exhibits common features of primitive ichthyosaurs such as: (1) the prefrontal has an antero-dorsal shelf projecting towards the orbit; (2) the upper temporal fenestra is small; (3) the postorbital and the squamosal meet laterally to the upper temporal fenestra; and (4) cylindrical centra. However, more derived ichthyosaur characters are seen with the frontal separated from the orbital dorsal margin by the contact of the prefrontal and postfrontal, which offer new clues to the early radiation of ichthyosaurs.  相似文献   

8.
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9.
A new stegosaur species, Jiangjunosaurus junggarensis, gen. et sp. nov., is erected based on a specimen collected from the Upper Jurassic upper section of the Shishugou Formation in the Junggar Basin, Xinjiang, China. It represents the first stegosaur from the Jurassic of Xinjiang and increases the diversity of the dinosaur fauna in the Shishugou Formation. The new genus is characterized by symmetrical and proportionally wide tooth crowns, a sub-rectangular axial neural spine seen in lateral view, and large openings on the lateral surfaces of the cervical centra. A preliminary character analysis suggests that this new taxon is more derived than the Middle Jurassic stegosaur Huayangosaurus but more primitive than most other known stegosaur species.  相似文献   

10.
A new Mazon-Creek-type fossil specimen is described as Sumixam maximus gen. and sp. nov., assigned to the taxon Archaeorthoptera Béthoux and Nel, 2002 (composed of Orthoptera and some fossil relatives): it exhibits one of the diagnostic character states of this taxon, which is the fusion of CuA (emerging from M + CuA) with CuP, or a branch of it. A more precise taxonomic assignment is out of reach. The new taxon exhibits a fusion of the anterior branch of MA with RP, and a point of divergence of MA and MP located near the point of divergence of CuA (from M + CuA), but lack a branching of CuPa. This unique combination of character states is probably derived with respect to a number of contemporaneous species. Sumixam maximus gen. and sp. nov. is most likely the closest known relative of the panorthopterans, which include all the recent Archaeorthoptera.  相似文献   

11.
A New Titanosaurian Sauropod from Late Cretaceous of Nei Mongol, China   总被引：2，自引：0，他引：2  
A specimen collected from the Upper Cretaceous Erlian Formation of Nei Mongol （Inner Mongolia）, China, represents a new genus and species of titanosaurian sauropod. The new taxon is named and described on the basis of the holotype and the only known specimen, which comprises several dorsal, sacral, and caudal vertebrae, several dorsal ribs, one anterior chevron, and much of the pelvis. Diagnostic features of the new species include a thick ridge extending down from the postzygapophysis on the lateral surface of the neural arch of the posterior dorsal vertebrae, a transversely oriented accessory lamina present between the anterior centroparapophyseal limina and the lateral centraprezygapophyseal lamina of the posterior dorsal vertebrae, long, anteroventrally directed caudal rib that bears two distinctive fossae on its posterior margin on the anterior caudal vertebrae and a prominent vertical ridge above the pubic peduncle on the medial surface of the ilium, among others. The ilium is pneumatic, a feature not common among non-avian dinosaurs. The new taxon has an unusual combination of primitive and derived character states. Preliminary character analysis shows a complex character distribution within the Titanosauriformes. Recent titanosauriform discoveries suggest that a significant radiation occurred in Asia early in the titanosauriform evolution.  相似文献   

12.
The Ordovician Changtu Fauna is recently discovered in the Xia' ertai and Hulan Groups in northernLiaoning-central Jilin. The fauna, containing 10 genera and 14 species (including 3 new genera, 9 new speciesand an unidentified species), is closely related in evolution with the Early Cambrian Qinghezhen Fauna. Thediscovery of this fauna is significant to the study on the age of the strata, Ordovician biostratigraphy and geo-logical evolution of the tectonostratigraphical terrane on the northern margin of the Sino-Korean plate.  相似文献   

13.
A new genus and species, Ramoferis amalia gen. et sp. nov., is described from the Early Devonian (Pragian) Posongchong Formation, Wenshan district of southeastern Yunnan, China. This plant has isodichotomous major axes, which also divide anisotomously distally to produce closely spaced lateral branches, often within fertile regions. The stalked round to reniform sporangia, borne laterally and spirally over several levels of branches, are distantly to moderately spaced or aggregated into distinct spikes. The stalks increase in width from the base to the sporangial junction resulting in a gradual transition between sporangium and stalk. Comparison with known zosterophylls shows that this plant is most similar to the genera Zosterophyllum and Wenshania, differing in the character combinations of sporangial shape, sporangium/stalk junction, stalk dimensions and orientation, and especially in both sterile and fertile branchlets being borne within the fertile zone. In addition, the observation and comparison indicate distinct variety in structure of sporangial border and suggest that the two-layered sporangium wall characterized by outer anticlinal layer and inner periclinal layer might represent potential synapomorphies, while the different dehiscence mechanism is an autapomorphy for each taxon in zosterophylls.  相似文献   

14.
A new species, referable to a new genus, is erected, and named the Sinokalligramma jurassicum gen. et sp. nov. It is the second finding of kalligrammatids in the Daohugou Formation. The origin and migration of the family Kalligrammatidae are discussed. The geological age and stratigraphic correlation of the Daohugou and Karabastau Formations are briefly reviewed and reassessed.  相似文献   

15.
Four new fossil genera and species of true bugs from the family Pachymeridiidae, Beipiaocoris multifurcus, Bellicoris mirabilis, Nitoculus regiUus, and Viriosinervis stolidus, are described. New specimens were collected from the Middle and Upper Jurassic non-marine sedimentary strata from the Jiulongshan and Yixian Formations of northeast China. The species Karatavocoris asiatica Becker-Migdisova, 1963, which was considered to be a member of the family Coreidae is transferred to the Pachymeridiidae. A new map of all known and newly discovered fossil pachymeridiid localities is given. The diagnosis of the family is modified.  相似文献   

16.
An almost complete skull, which was collected from the Upper Cretaceous of the Bayan Mandahu area in Inner Mongolia, China by the Sino-Canadian Dinosaur Project, is described and assigned to a new genus of protoceratopsid dinosaur, Magnirostris dodsoni gen. et sp. nov. This new taxon is distinguished from other protoceratopsids by the robust rostral bone and the existence of incipient orbital horn cores. The existence of an additional antorbital fenestra indicates a close relationship between Magnirostris and Bagaceratops.  相似文献   

17.
Abstract: The close affinity between Edmontosaurus and Shantungosaurus is corroborated on the basis of the following shared features: an occipital condyle deflected strongly posteroventrally; a posterodorsally reflected, lip-shaped oral margin of the premaxilla, with a deep, oval concavity at the anteromedial corner of the bone; a well-demarcated posterodorsal margin of the deeply excavated circumnarial fossa formed by a prominent arched ridge along the entire posterior half of the lateroventral border of the nasal; an anteroposteriorly broad jugal process of the postorbital; a strongly concave dorsal surface of the paired frontals; seven teeth per alveolus in the middle of the dentary tooth row; and a circular distal blade of the pubis that is much more expanded ventrally than dorsally. A revised phylogenetic analysis of Hadrosauroidea recovers a sister taxon relationship between Edmontosaurus and Shantungosaurus. Kerberosaurus is recovered as the sister taxon to the clade formed exclusively by these two genera. The clade Edmontosaurini could be defined as the least inclusive clade containing Kerberosaurus and Edmontosaurus, which is currently composed of the genera Kerberosaurus, Edmontosaurus, and Shantungosaurus. Zhuchengosaurus and Huaxiaosaurus, both from the Upper Cretaceous Wangshi Group in Zhucheng, are interpreted as junior synonyms of Shantungosaurus. Kundurosaurus is likewise considered a junior synonym of Kerberosaurus. The strict consensus tree together with biogeographic information indicates that the clade Edmontosaurini originated in Asia and subsequently dispersed into North America.  相似文献   

18.
Chitinozoans collected from upper Tremadocian to lower Floian strata of Chenjiahe section, Yichang, western Hubei, China comprise six species belonging respectively to the genera Euconochitina including a new species, Euconochitina fenxiangensis, Lagenochitina and Bursachitina, together with Desmochitina sp. and Eremochitina sp. The chitinozoan succession across the interval is correlated with relevant conodont and chitinozoan biozones and two new regional chitinozoan biozones, the Lagenochitina destombesi Biozone and the Euconochitina symmetrica Biozone are proposed based on their stratigraphic ranges in the Fenxiang to Honghuayuan formations in the Chenjiahe section.  相似文献   

19.
This paper reports for the first time on the microfossils discovered in the black cherts of the basal part of the Lower Cambrian Shuijingtuo Formation at Miaohe village, Zigui County, Hubei Province, all of which were observed in thin sections. Nine genera, 9 species and 3 indeterminate species (including a new species) are described. According to these microfossils, the conclusion is made that the microfossil zone may be equivalent to the small shelly fossil assemblage zones 2—3 of the Meishucun stage. They have provided another important line of evidence for the correlation of the Sinian-Cambrian boundary strata with those of the adjacent areas.  相似文献   

20.
A new species of Araucaria, Araucaria beipiaoensis sp. nov., collected from the Middle Jurassic Tiaojishan Formation, southern hill of Shebudai village, near Beipiao city, western Liaoning is based on a permineralized female cone, which is ovate to elliptical in shape, about 11 cm × 7 cm × 4.5 cm in size. The cone bears rhomboid bracts that are spirally attached, texture thicker, with wings on both sides, with a detached lamina-like apex at the tip. In inner structure the ovuliferous scales are thicker and fused with bracts at the end with a ligular sulcns. There is one wingless ovule/seed per seed-scale complex embedded in the ovuliferous scale tissue, with the micropyle directed toward the cone axis. The ovules/seeds are long ovate or elliptical in shape, 1 cm long and near the base about 3 mm in diameter; the ovule/seed integuments have begun differentiation into 3 layers： the sarcotesta, sclerotesta, and endotesta. The nucellus is free from the enclosing integuments except in the chalazal region where it is fused to the inner layer （endotesta） of integument. Some ovules show cellularized nucellar tissue. Mature seeds exhibit the papery-thin wavy nucellus characteristically near to the micropyle. The embryonic tissue appears to be four cotyledons. The morphology and structure of the cone shows a close relationship to the araucarian cones of fossil and living genera but differs from any known species. The new species is distributed in the Middle Jurassic of the northern hemisphere, especially Asia, and has important significance for the evolution of the Family Araucariaceae.  相似文献   

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