摘要
本文记述了产自湖南下石炭统测水组的右旋轮藻类Gemmichara hunanensis sp.nov.和新疆上二叠统锅底坑组的左旋轮藻类 Leonardosia iur panensis sp.nov..Gemmichara hunanen-sis sp.nov.系我国石炭纪轮藻的新发现。文中讨论了含轮藻化石地层的时代及轮藻的生活环境.
Two new species of Palaeozoic charophytes, Gemmichara hunanensis sp. nov.and Leonardosia turpanensis sp. nov. are described in the present paper. The for-mer is derived from the Lower Carboniferous Tseshui Formation of Lengshuijiang,Central Hunan, and the latter from the Upper Permian Guodikeng Formation ofthe Turpan Basin, Xinjiang. Records of Palaeozoic charophytes are rather rare inthe literature, with only 5 species belonging to 5 genera so far known from theCarboniferous. The presence of G. hunanensis adds a new member to the Palaeo-zoic charophytes at both specific and generic level. When the genus was erected,it was known as a Permian fossil. Since the discovery of the present species, itsgeological range has been extended to the late Early Carboniferous, i. e., Visean. A fairly large amount of Gemmichara hunanensis gyrogonites has been collec-ted from the middle part of the upper member of the Tseshui Formation. Thisformation is a set of coal-bearing series 95 m in thickness, and can be dividedinto two members. The lower member is characterized by coal seams, and com-posed of greyish black mudstone, siltstone and fine sandstone interbedded withgreyish white quartzose sandstone, yielding siderite nodules. The upper membermay be subdivided into two parts; the lower part is composed of greyish whitequartzose sandstone, dark grey-greyish black mudstone and siltstone with thin-bedded coal layers, while the upper part is composed of light grey, greyish greenand purple silty mudstones, siltstones and fine sandstones with dark grey argilla-ceous limestone and thin-bedded marl, occasionally with coal seams. The TseshuiFormation conformably overlies the Shihtengtze Formation and conformably under-lies the Tzumenchiao Formation. Both of the Shihtengtze and TzumenchiaoFormations are mainly composed of limestone and yield rich faunae of the Viseanage. In the Tseshui Formation, rich fauna and flora have been studied, whichmainly comprise the plants Cardiopteridium spetsbergense, Triphyllopteris collombiana,Adiantites gothani, Rhodeopteridium hsianghsiangense, Archaeocalamites prolixus, Lepi-dodendron cf. robertii, L. sp., the brachiopods Punctopirifer kusbassica, Plicochone-tes elegans, Gigantoproductus hemisphaericus, Camarotochia sp., Plectogyra exelikta,Rhipidomella sp., the bryozoans Rhombopora sp., Fenestella sp., Tabulipora sp.,the corals Yuanophyllum sp., Dibunophyllum sp., the fusulinids Eostaffella endothy-roidea, E. sp., the marine bivalve Aviculopecten sp. and brown algae (Zhang etal., 1980; Wu et al., 1986). Gyrogonites of G. hunanensis are well-preservedtogether with their delicate prolonged apical projections. In association with them are small individuals of brachiopods, bivalves and fragments of plant pinnules. Itis inferred that G. hunanensis might live on shore. Leonardosia turpanensis, another charophyte described in the present paper,was derived from the Guodikeng Formation of Taoshuyuan, 5 km NE of Daheyantown, Turpan Basin, Xinjiang. the Guodikeng Formation is a set of greyishgreen, dark purple, greyish black mudstones, silty mudstones intercalated withsandstone and lenses of conglomerate with atotal thickness of 83-140 m; its lowerpart is mainly greyish green in colour. It is conformably in contact with the over-lying Lystrosaurus-bearing Lower Triassic Jiucaiyuan Formation and the under-lying Upper Permian Wutonggou Formation. Based on palaeontological evidences.from the fossil vertebrates Jimusaria taoshuyuanensis and Turfandon bogdaensis, gas-tropods, abundant plant fossils and palynological evidences as well, the GuodikengFormation is late Late Permian in age. The charophyte remains are preserved in the greyish black silty mudstone inassociation with fresh water gastropods. They might live in streams, swamps, oron shallow shore of lakes.
出处
《微体古生物学报》
CSCD
北大核心
1990年第1期9-17,98,共9页
Acta Micropalaeontologica Sinica
