云南施甸早石炭世早期香山组的一些珊瑚化石

SOME RUGOSE CORALS FROM THE XIANGSHAN FORMATION OF THE EARLY LOWER CARBONIFEROUS IN SHIDIAN COUNTY, WESTERN YUNNAN

云南西部施甸地区早石炭世早期地层称香山组,分上、下两段。下段建立四射珊瑚Rotiphyllum yudongense—Commutia crassoseptata—Antikinkaidia typica组合带。上段下部建立Thuriantha sinensis-Tachylasma shidianense组合带。本文共描述四射珊瑚11个属,14个种和2个未定种(其中包括2个新属,12个新种)。

The rugose corals dealt with in the present paper were collected from the Xiangshan Formation of the early Lower Carboniferous in Shidian County, western Yunnan. The early Lower Carboniferous strata, are called the Xiangshan Formation, it may be subdevided into two members: Upper and Lower. In this paper 12 genera. 15 species and 3 indeterminate species (including 2 new genera and 12 new species) are described. They may be devid-ed into two rugose coral assemblages as follows:Lower assemblage: Rotiphyllum yudongense - Commutia crassoseptata - Antikinkaidia typica assemblage, including Rotiphylium yudongense (sp. nov.), R. dilatatum (sp. nov.), R. crassoseptatum (sp. nov.), Commutia crassosepiata (sp. nov.), A nlikinkaidia typica (sp. nov.), A. sp., Parametrio phyllum symmetricum (gen. et sp. nov.), Pentaphyllum eras sos septaturn (sp. nov.), Shidiano phyllum staurum (gen. et sp. nov.), Tachylasma sp. The fossil corals of this assemblage are simple, small in size and conical in shape, without dissepiments. They are not in intergrowth with compound rugose corals and genus Cystophrentis has not been found. The coral fauna possibly lived in the deep and calm sea water. It differs from that of South China, but closely resembles that of the Europe. The coral fauna belongs to the Gattendorfia Zone and the lower part of the Cystophrentis Zone.Upper assemblage: Thuriantha sin.nsis - Tachylasma shidianense assemblage, containing Tachylasma shidianense (sp. nov.), Thuriantha sinensis (sp. nov.), Fascicule phyllum omaliusi (Edwards et Haime), Caninia cornucopiae Michelin, Sychnoelasma konincki (Edwards et Haime). The upper assemblage belongs to the upper part of the Cystophrentis Zone.The description of the new genera is given as follows:Genus ShidianophyllumZ. J. Wang (gen. nov.)Type species: Shidiano phyllum staurum Z. J. Wang (gen. et sp. nov.) Diagnosis: Simple corals, small in size and conical in shape; with major septa only. In early-neanic stages, their septa fewer and thickened; cardinal, counter and two alar septa very thick and connected in a cross form in the centre. In adult stage, the number of septa increased; cardinal, counter and two alar septa thinned; cardinal septum, counter septum and some of major septa connected in center. In cardinal quadrants and counter quadrants septa slightly arranged in pinnate. In senile stage, the ends of septa shortened from the cen- tre, and slightly thickened, and some of them connected. Cardinal septum straight and long, extending to the centre, without dissepiments.Remark: This new genus is similar to Tetralasma Schidewolf, but it differs from the later for its four septa conneting at the centre in the early-neanic stage, and many and long septa in the adult stage.Occurrence: Early Lower Carboniferous, Yunnan of ChinaGenus Parametriophyllum Z. J. Wang (gen. et. sp. nov.)Type species: Parametriophyllum Z. J. Wang (gen. et sp. nov.)Diagnosis: Coral simple, small, long-conical in shape. Peripheral stereozone very thick. Major septa long. Septa thickened and connected at the centre. Stereocollumella prominent. Minor septa short or absent. Septa have flat carina. Tabulae arched and widely spaced. No dissepiments.Remarks: This new genus somewhat resembles Metriophyllum, but differes from it in the corallum of the new genus is long-conical and the peripheral stereozone is very thick.Occurrence: Late Devonian and Early Lower Carboniferous; Yunna of China.