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《Palaeoworld》2020,29(4):682-694
A conodont fauna from the uppermost part of the Beiliu Formation at the Nalai section (Guangxi, South China) is studied. Four species of Bipennatus Mawson are described, of which B. hemilevigatus n. sp. is differentiated by a short sulcus flanked by a smooth left margin and a nodose right margin, and B. planus n. sp. is characterized by a distinctly flat, smooth, and narrow platform in the middle part of the blade above the basal cavity. Another species in open nomenclature, Bipennatus? sp., is distinguished by an extremely primitive sulcus or a totally fused and adenticulate ridge above the basal cavity. This paper also reports occurrences of ‘Ozarkodina’? sp. B, Polygnathus nalaiensis n. sp., and P. costatus costatus Klapper. The conodont fauna situates the investigated samples in the lower Eifelian costatus Zone. Taking specimens of Bipennatus from the Hillesheimer Mulde and Bergischen Land (Germany) into consideration, the conodont material furnishes new data on the diversification and phylogeny of this genus. A taxonomic revision of Bipennatus is conducted, and this genus includes B. bipennatus (Bischoff and Ziegler), B. hemilevigatus, B. montensis (Weddige), B. planus, B. scalaris (Mawson), and B. mayri (Uyeno), the latter two are raised herein to species level. More importantly, the prominent diversification of Bipennatus in the costatus Zone cannot be interpreted by previously proposed hypotheses on the phylogeny of Bipennatus, which specifically focus on the development of a characteristic sulcus on the upper margin above the basal cavity. It is apparent that the ornamentation of the narrow or wide platform above the basal cavity is more complicated and variable than previously estimated, and that this genus needs further investigation, especially on the lowest occurrences of its assigned species.  相似文献   

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《Comptes Rendus Palevol》2016,15(5):453-459
Radiolarians are usually abundant in chert sequences and they have thus been widely used for the biostratigraphy of deep-water sediments. However, there are many difficulties in the correlation of radiolarian biostratigraphic schemes with the standard conodont zones. In this study, 21 radiolarian species were extracted from the Gufeng Formation that crops out in the Luojiaba (LJB) section (western Hubei, China), together with 5 co-occurring conodont species. In this way, it is the first time that the Pseudoalbaillella globosa, Follicucullus monacanthus and F. scholasticus radiolarian zones can be directly correlated with the Jinogondolella nankingensis gracilis, J. aserrata and J. postserrata conodont zones. Accordingly, the 3 radiolarians zones are now firmly correlated with the Roadian to middle Capitanian interval (Middle Permian).  相似文献   

4.
《Palaeoworld》2015,24(4):454-459
The extensive Devonian marine deposits of South China have yielded few articulated crinoid cups or theca. Two Eifelian specimens, from the Gupa Member, are the first ones reported from the Yingtang Formation, Eifelian, from the Ma’anshan section, Guangxi, South China. The new taxon Guangxicrinus xiangzhouensis n. gen. n. sp. is the first report of a marsupiocrinid in China, extending the paleogeographic range of the family into the Paleotethys and the stratigraphic range of the family upward from the upper Silurian into the lower Middle Devonian, Eifelian. The occurrence of Halocrinites sp. is the third occurrence of a cupressocrinitid in China and extends the paleogeographic range from Yunnan to Guangxi.  相似文献   

5.
Gobioid fishes collected in Nha Trang and Van Phong bays (Vietnam) represented by 44 species, including 30 species continuously associated with soft bottoms in the open parts of the bays with normal marine conditions are reviewed. A new species, Navigobius khanhoa sp. n., is described. This species differs from other species of the genus in much higher number of rays in the second dorsal fin (26), smaller size of the mouth, teeth on the jaws arranged in a single row, and other characters. Four species from the genera Acentrogobius, Eviota, Favonigobius, and Gnatholepis have not been identified to the species, and, most likely, some of them are new for science. Nine species are recorded in the fauna of Vietnam for the first time: Aulopareia unicolor, Bathygobius hongkongensis, Egglestonichthys bombylios, Glossogobius circumspectus, Oplopomops diacanthus, Oxyurichthys auchenolepis, Tomiyamichthys ex gr. russus, Tryssogobius porosus, and Valenciennea immaculata. An occurrence of Glossogobius olivaceus in the fauna of Vietnam is confirmed. Three species, G. olivaceus, Oligolepis acutipennis, and Periophthalmus kalolo, are recorded in the Cai River delta for the first time. A new synonymy is established: Eviota gurjanovae (Prokofiev, 2007) = E. prasina (Klunzinger, 1871). The current state of knowledge of Gobiidae fauna of Vietnam is discussed, and the updating of the species composition of Gobiodontini of Nha Trang Bay is presented in addition to the species list published earlier (Prokofiev, 2007).  相似文献   

6.
Dendroid graptolites from the Middle Devonian (Givetian, middlePolygnathus varcus Biozone) of the Rheinisches Schiefergebirge are described for the first time. The fauna of the Burgberg locality south of the Brilon reef comes from a black shale layer in a succession of calcareous debris flows. The fauna includes five species ofDictyonema andRuedemannograptus described in open nomenclature. The fragmentation of the material is conside-red as an indication of post-mortem transport.   相似文献   

7.
《Geobios》2018,51(6):559-570
The outcrops of the Xiangshan Group have been studied since the beginning of the twentieth century, yielding a rich macroflora (the Xiangshan Flora), mainly from the lower part of the Xiangshan Group (South Xiangshan Formation). Nevertheless, no palynological data have been published so far from the South Xiangshan Formation. The present study provides the first palynostratigraphic data of the South Xiangshan Formation. More than 50 fossil taxa from 30 fossil genera have been identified, allowing for a more accurate dating. The most characteristic taxa are Polycingulatisporites triangularis, Quadraeculina anellaeformis, Manumia delcourtii, Ischyosporites variegatus, Callialasporites turbatus, C. trilobatus, C. minus, and Sestrosporites pseudoalveolatus, suggesting a late Toarcian-late Aalenian age for the South Xiangshan Formation. These results are consistent with previous studies suggesting a middle-late Early Jurassic age for this formation; consequently, the most probable age for the South Xiangshan Formation is late Toarcian (late Early Jurassic).  相似文献   

8.
Journal of Ichthyology - From the coast of Vietnam, Nemipterus biendongensis sp. n. has been described, similar in body proportions to N. balinensoides, but differing from this species in a...  相似文献   

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《Palaeoworld》2022,31(3):402-418
Sphenophyllum Brongniart constitutes a common and important element in the Carboniferous and Permian floras around the world, but its records in the Devonian Period are limited and remain to be investigated with respect to their morphology, anatomy, and distribution. Diversity of Sphenophyllum during Late Devonian in South China was significant with the presence of the well-known species including S. lungtanense Gothan and Sze, S. pseudotenerrimum Sze, and S. changxingense Huang et al. In this article, we describe a new species of the genus, S. fanwanense n. sp., from the Fanwan section of Changxing County, Zhejiang Province, characterized by having at least two orders of axes, with six spoon-shaped leaves attached at the node. A comprehensive review of previous records of Sphenophyllum from the Upper Devonian of South China shows that at least four species (S. fanwanense, S. lungtanense, S. pseudotenerrimum and S. changxingense), each with distinct leaf morphology, occur in South China in the Late Devonian, mostly from the Wutong Formation (Famennian). Given the lack of concrete evidence for anisophylly or heterophylly among the Devonian Sphenophyllum species (and more broadly, the Devonian sphenopsids), we suggest that the development of these features later in the Carboniferous and Permian periods was likely related to an increase in complexity of forest communities through time.  相似文献   

11.
New spiriferids (Brachiopoda) are described from the Lower and Middle Devonian of northeastern Russia: Tatjanaspirifer iskrensis sp. nov. and T. magnificus sp. nov. (family Reticulariidae); Cyrtina inveterata Baranov, sp. nov. and Blodgettospirifer gen. nov. with type species B. lezhoevi sp. nov. (family Cyrtinidae).  相似文献   

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《Geobios》2016,49(6):459-467
Traditionally, the lower boundary of the Emsian (Lower Devonian) has been defined as the base of the dehiscens Zone marked by the first entry of the conodont Polygnathus dehiscens. However, following taxonomic revision of P. dehiscens, the current practice is to use the first appearance of P. kitabicus to define the base of the Emsian. As a result, specimens previously identified as P. dehiscens from South China need to be thoroughly reviewed. Careful examination of the oral and aboral features of the platform reveal that most specimens previously described as P. dehiscens from nine sections in Guangxi and Yunnan actually refer to P. excavatus excavatus or P. excavatus ssp. 114. In the South China Block, widespread and massive deposition of Devonian carbonates began during the time of the excavatus Zone, whereas the kitabicus Zone is probably located in the underlying strata, which mainly comprise marine siliciclastic rocks. Thus, the precise level of the lower boundary of the Emsian in South China is still unknown.  相似文献   

14.
Two new cutthroat eel species are described from Vietnam. Dysomma intermedium sp. nov. has a relatively long trunk, being about half of head length and anal-fin origin more than twice pectoral-fin length behind the pectoral-fin tip; pectoral fin well developed; dorsal-fin origin over or slightly in front of base of pectoral fin; two intermaxillary teeth; four or five compound teeth on ethmovomer; single row of seven or eight teeth on lower jaw; total lateral-line pores 70–76; and 21 pre-anal and 118–124 total vertebrae. Dysommina brevis sp. nov. differs from congeners by having a trunk shorter than head length, its length 11.1%–11.8% TL; a short pre-anal length 24.6%–25.6% TL, eye diameter 11.8%–12.3% head length; three large and one or two small teeth on ethmovomer; and fewer teeth on the upper and lower jaws. In addition, a specimen representing the first record of Dysommina orientalis in Vietnamese water is documented.  相似文献   

15.
Archaeopteris macilenta is one of the most widespread plants in the Late Devonian.Based on fossils from the Frasnian Huangjiadeng Formation,Yichang District of Hubei Province,for the first time we study in detail the anatomy of this progymnosperm plant in South China.Ultimate axes are protostelic with three xylem sympodia and lack secondary tissue.Penultimate axes are eustelic,bearing eight sympodia and a thin band of secondary xylem.Radially symmetrical sympodia of mesarch primary xylem produce traces of appendages in a spiral arrangement.Archaeopteris macilenta and A.halliana (A.roemeriana) are dominant in the Frasnian and Famennian,respectively.Comparisons with these two species from other tectonic plates indicate consistent stelar architectures.Global spread,continuous occurrence,and identical anatomy during the Late Devonian indicate that Archaeopteris survived the Frasnian-Famennian extinction event.In this time,endemic genera and cosmopolitan taxa,including Archaeopteris,suggest the palaeogeographic isolation of South China and certain associations with other plates.  相似文献   

16.
Silicified polyplacophorans are common in the Lower Devonian Garra Formation in New South Wales. Four taxa occur within the lower 237 m of the formation at 14 horizons associated with an abundant and diverse fauna. Chelodes calceoloides Etheridge ranges through the section. New taxa are Chelodes cordatus sp. nov., Acutichiton depressolatus sp. nov., and Jugochiton patulus gen. and sp. nov. A single plate of an indeterminate genus occurs in the lower portion of the Camelford Limestone.  相似文献   

17.
New thelodont scales from the type section of the Khush-Yeilagh Formation, between Shahrud and Shahpasand(Iran), are described. They are provisionally referred to as Skamolepis sp. and Turinia cf. hutkensis. Together with T. hutkensis from South-East Iran and some undescribed scales from the Givetian of Australia, these specimens are some of the youngest thelodont scales known to date, since they are of Lower Eifelian age.  相似文献   

18.
Minostrobus chaohuensis Wang was previously known only as a lycopsid megasporangiate strobilus from the Upper Devonian of Anhui Province, South China. Our comprehensive study of the newly collected materials reveals the details of its morphology, anatomy, and reproduction, which allow us to emend its generic and specific diagnoses. M. chaohuensis is reconstructed as a plant with multi-dichotomous branching system, helically arranged leaves, and monoecious and monosporangiate strobili (i.e., separate megasporangiate and microsporangiate strobili in one individual). The anatomy of both fertile and sterile portions of Minostrobus indicates that the exarch primary xylem strand is the solid protostele, with the peripheral protoxylem ridges and Williamson's striations in metaxylem tracheids. The key reproductive and anatomical characters suggest that Minostrobus chaohuensis is far more likely to represent a distal shoot of pseudo-herbaceous or arborescent lycopsids within the order Isoëtales sensu lato. It is suggested that the monosporangiate-strobilus clade in the Isoëtales may include primitive, monoecious taxa in the Late Devonian and advanced, dioecious ones in the Carboniferous. The hypothesis that the more phylogenetically advanced monosporangiate-strobilus clade might have well diverged from the basal bisporangiate-strobilus clade of arborescent lycopsids by the Late Devonian is further supported.  相似文献   

19.
The Yujiang Event is reported here as a newly recognized event that occurred during the deposition of the Early Devonian Yukiang Formation in Liujing, Guangxi, and its equivalents in South China. The first episode of the Yujiang Event is characterized by the extinction of biostrome that is constructed mainly by colonies of rugose coral, tabulatimorph coral and bryozoan as well as the extinction of evolved biota including some brachiopods, bivalves, etc. The age of the first episode of the Yujiang Event dated by conodonts is at the beginning or the lower part of the Polygnathus nothoperbonus Zone. The main episode of Yujiang Event is evidenced by the extinction of the Rostrospirifer tonkinensis Fauna (sensu lato) at the top of Yukiang Formation and by the sudden occurrences of the dolostones and dolomitic limestone of the overlying Moding Formation. At the basal part of the Moding Formation, the new finding of conodont Polygnathus nothoperbonus and dacryconarids Nowakia (N.) barrandei indicates that this episode of Yujiang Event may occur in the upper part of the Polygnathus nothoperbonus Zone. Overlying the Yukiang Formation and its equivalent beds, various lithic deposits correspondingly yielding different biota can be seen widely in many localities and sections in South China and northern Vietnam. Therefore, the Yujiang Event can be recognized not only as a biotic extinction event, but also as a geological event.  相似文献   

20.
According to newly collected and well preserved specimens,herbaceous lycopsids Colpodexylon gracilentum Dou and Colpodexylon laminatum Dou from the late Middle Devonian of Xinjiang,NW China are reduced to C.gracilentum,for which a neotype is designated and emended diagnosis is given.Colpodexylon gracilentum has leaves with three nearly equal segmems,an elliptical sporangium adaxially attached by a pad on the isomorphic sporophyll.  相似文献   

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