Songzhu Gu

A late Changhsingian (Late Permian) deepwater brachiopod fauna from the Talung Formation at the Dongpan Section, southern Guangxi, South China

Abstract This paper describes a unique deepwater brachiopod fauna from the upper part of the Talung Formation at the Dongpan Section, southern Guangxi, South China. This brachiopod fauna includes 10 species belonging to 10 genera. New taxa are Anidanthus mucronata n. sp., Dongpanoproductus elegans n. gen. and sp., Costatumulus dongpanensis n. sp., and Spinomarginifera semicircridge n. sp. This fauna is characterized by small, thin-shelled species with high abundance and low diversity, and therefore is different in generic and species composition from the coeval faunas of the Late Permian limestone facies in South China. The brachiopod fauna can be safely assigned to the latest Changhsingian as indicated by the presence of abundant Paracrurithyris pigmaea, the immediately underlying radiolarian Neoalbaillella optima Zone of late Changhsingian age, and the overlying ammonoid Ophiceras sp. cf. O. tingi Tien of the lowest Triassic. This fauna is most likely to have lived in a deepwater environment as indicated by coexistence with the radiolarian Latentifistularia, small thin-shelled brachiopods, and the dominance of silica-bearing mudstone.

UPPERMOST CHANGXINGIAN (PERMIAN) RADIOLARIAN FAUNA FROM SOUTHERN GUIZHOU, SOUTHWESTERN CHINA

Abstract A unique radiolarian fauna recovered from the top part of the Changxingian stage in south Guizhou, Southwest China, includes at least nineteen species one of which is new. The fauna is mainly composed of Permian species extensively distributed all over the world, such as Hegleria mammilla (Sheng and Wang, 1985); Ishigaum trifustis De Wever and Caridroit, 1984; Foremanhelena triangula De Wever and Caridroit, 1984; Triplanospongos dekkaensis (Noble and Renne, 1990); Nazarovella gracilis De Wever and Caridroit, 1984; and Nazarovella inflata Sashida and Tonishi, 1986, among others. Besides these species, a new radiolarian assemblage, represented by Copicyntra ziyunensis new species; Copiellintra fontainei (Sashida, 2000); Klaengspongus spinosus Sashida, 2000; and Paroertlispongus? sp., was discovered in South China. The assemblage only occurs in less than 10 m siliceous rock strata under the Permian-Triassic boundary at south Guizhou, Guangxi, and north Sichuan. Although only a few new species appeared during this period, they are very important for understanding both the radiolarian extinction at the end of the Permian and the relation between the Paleozoic and Mesozoic Radiolaria.

CHANGXINGIAN (UPPER PERMIAN) RADIOLARIAN FAUNA FROM MEISHAN D SECTION, CHANGXING, ZHEJIANG, CHINA, AND ITS POSSIBLE PALEOECOLOGICAL SIGNIFICANCE

Abstract A well-preserved radiolarian fauna reported from the Changxing Formation in the Meishan D Section, Changxing, Zhejiang, China, mainly includes abundant Entactinia itsukaichiensis, Grandetortura nipponica, Copicyntra robustodentata, Lepingosphaera stauracanthus, and a few Entactinia meishanensis n. sp., Entactinia? sp., Entactinosphaera cimelia, Triaenosphaera sp., Tetragregnon sp., Paracopicyntra ziyunensis, Copicyntroides sp. cf. C. asteriformis, Copicyntroides sp., and Ishigum trifustis, with the conodont Neogondolella subcarinata Zone. One new species, Entactinia meishanensis, is described in this paper. This radiolarian fauna is characterized by low abundance and low diversity, and apparently occurred in a water depth of 150–200 m.

TAXONOMY OF ORDER LATENTIFISTULARIA (RADIOLARIA) FROM THE LATEST PERMIAN IN SOUTHERN GUANGXI, CHINA

Abstract Caridroit, De Wever, and Dumitrica (1999) promoted stauraxon (Radiolaria) to an order, order Latentifistularia, and De Wever et al. (2001) proposed a classification using family and genus levels. However, the taxonomy of this order in genus level is still problematic because some genera were named according to broken specimens. A radiolarian fauna with a high diversity was collected from the late Changxingian in southern Guanxi, China. These specimens are very well preserved so that they are rare material for roundly describing the characters of some genera. They are identified as 42 species belonging to 16 genera and 5 families. Fifteen new species and one new genus are described, some genera are discussed, and some species are revised.

A LATE PERMIAN TO EARLY TRIASSIC BIVALVE FAUNA FROM THE DONGPAN SECTION, SOUTHERN GUANGXI, SOUTH CHINA

Abstract A bivalve fauna from the Permian—Triassic interval of the Dongpan section, Guangxi, South China is described herein. This bivalve fauna includes 16 species belonging to 10 genera. New taxa are Euchondria fusuiensis, Palaeoneilo qinzhouensis, and Claraia liuqiaoensis. Bed 12 of the interval (Talung Formation) contains the typical late Late Permian ammonoids: Huananoceras sp., Laibinoceras cf. L. compressum Yang, and Qiangjiangoceras sp. Bed 13 (Luolou Formation) contains typical Early Triassic bivalves Claraia dieneri Nakazawa, C. cf. C. wangi (Patte), and C. griesbachi (Bittner), which coexist with the earliest Triassic ammonoid Ophiceras sp. The bivalve and ammonoid distributions at the Dongpan section indicate that bed 12 should be assigned to the Late Permian, and bed 13 should be assigned to the Early Triassic. From the early Changhsingian to the Induan, the byssal notches of Claraia species tend to become progressively narrower, and change from being ventrally extended to being horizontally extended. The species level diversity of Claraia also increases through this interval.

Latest Permian deep-water ostracods from Southwestern Guangxi, South China.

A very diverse ostracod fauna was discovered in the latest Permian strata of the Dongpan section, southwestern Guangxi, South China. Fifty-one species belonging to twenty-eight genera were identified and described, including two new species (Bairdia dongpanensis n. sp. and Spinomicrocheilinella anterocompressa n. sp). This type of assemblage, with nineteen palaeopsychrospheric species and four pelagic species, is the first world-wide deep-water ostracod fauna reported from the latest Permian strata and the first one recorded in the Permian of China. The palaeoenvironmental analysis allows one to propose an evaluation of the bathymetry variation along the Dongpan section.

Latest Permian Entactinaria (Radiolaria) from southern Guangxi, China

A highly diverse and well-preserved latest Permian radiolarian fauna was obtained from muddy siliceous rocks and siliceous mudstones of the Dalong Formation, southern Guangxi, China. Specimens of the Order Entactinaria were selected for taxonomic study. Thirty-four species, among which were nine new species and twelve unidentified species, are included in this investigation. The nine new species are Entactinia wangi, Entactinia minuta, Entactinia sashidai, Trilonche textiles, Triaenosphaera variabilis, Triaenosphaera megacantha, Provisocyntra densa, Provisocyntra ormistoni and Wuyia dongpanica. Permian species of the Family Spongentactiniidae Nazarov are reported first and the extinction pattern of the Order Entactinaria is discussed.

ALBAILLELLIDAE (RADIOLARIA) FROM THE LATEST PERMIAN IN SOUTHERN GUANGXI, CHINA

Abstract A delicate and well-preserved latest Permian radiolarian fauna was obtained from muddy siliceous rocks and siliceous mudstones in the Dongpan Section, southwest Guangxi, China. The specimens of family Albaillellidae in the fauna have been selected for taxonomic study in this paper. Two genera and 14 species belonging to this family are recognized and described, including three new species and one new subspecies, namely Neoalbaillella minuta, Albaillella flabellata, Albaillella fida, and Albaillella yaoi longa, respectively. This assemblage is correlated to the Neoalbaillella optima Assemblage Zone. Its biostratigraphic significance and the final extinction of Albaillellidae at the end of Late Permian are observed and discussed herein.

A new genus of Entactiniidae (Radiolaria) from the Upper Permian of South China

Four new species and one indeterminate species of radiolarians from the Changxiangian (Upper Permian) of southern Guangxi, South China are introduced. They all belong to one new genus: Megaporus n. gen. This new genus is characterized by two concentric spherical shells with pentagonal and hexagonal pore frames composed of thick but narrow bars, which is very similar in morphology to some genera within the Mesozoic subfamily Pantanelliinae Pessagno (1977), but differs from the latter in possessing initial spicules within medullary shell.

A new genus Liaous of early Anisian Stage (Middle Triassic) brachiopods from southwestern China: systematics, reassessment of classification of the Spiriferinioidea, community paleoecology, and paleoenvironmental implications

Abstract. This paper describes a new genus Liaous, with L. shaiwensis He and Chen n. gen. n. sp. as the type species, from the Xinyuan Formation of Anisian age in Ziyun, southern Guizhou, China. The phylogenetic tree revealed by the parsimony analysis shows that Liaous is closely allied to both Mentzelia Quenstedt, 1871 and Paramentzelia Xu, 1978 of the subfamily Mentzeliinae. A new classification scheme for the Spiriferinoidea is also proposed based on a phylogenetic tree of the superfamily indicated by parsimony analysis. The Spiriferinoidea includes three families and nine subfamilies. Three new subfamilies—Madoinae He and Chen, new subfam., Qinghaispiriferininae He and Chen, new subfam., and Triadispirinae He and Chen, new subfam. are proposed. Liaous shaiwensis He and Chen n. gen. n. sp. is found in the Posidonia wengensis-Liaous shaiwensis (P-L) paleocommunity, which is dominated by r-strategists (i.e., organisms defined by a fauna with a high dominance and small body sizes) and has a low diversity and high dominance. The P-L paleocommunity therefore has little similarity to its coeval communities from the Anisian Stage of South China and instead it appears more similar to the Lower Triassic shelly faunas in community structures. This paleocommunity is interpreted to have inhabited a relatively deep, low-energy, dysaerobic offshore basin/slope setting with the influence of episodic storms.