摘要
文章通过贵州盘县新塘原下二叠统下部紫松阶珊瑚化石的分析,将该地层划归上石炭统上部.描述上石炭统威宁阶、过岩阶和紫松阶的四射珊瑚6属7种,其中5新种.通过对这些珊瑚的形态构造进行了剖析,略述了该地区在晚石炭世的环境特征.
The Upper Carboniferous rugose corals under study were collected from Xintang of Panxian, Guizhou, with 6 genera and 7 species (including 5 new species), namely. Fomichevella panxianensis sp. nov., Anfractophyllum ivanoviforme sp. nov., Arctophyllum mapingense (Lee et Yu), Kionophyllum xintangense sp. nov. Lytvopnyllum raricystosum sp. nov., Ivanovia podolskiensis Dobrolyubova and I. xintangensis sp. nov., in association with the fusulinids Sphaeroschwagerina and Triticites. These corals are identical with or closely related to those from the Weiningian and Mapingian Upper Carboniferous in South and Southwest China, and also closely related to those from the Kasimovian of former USSR. and Poland.
Based on morphological characters there are solitary, fasciculate and massive types of corals, The massive corals account for over 42% the total number of species in this area, representing an ecotype of corals growing in the beachy and shallower water environments with a strong motive power.
Fomichevella panxianensis sp. nov. (Pl. I. figs. 1a. b)
Diagnosis Fasciculate corallum with corallites measuring 16-20mm in diameter. Septa (30-31)+(30-31) in number; major ones occupying about 1/3 the diameter of corallites; minor ones about 1/6-1/5 as long as the major ones. Dissepimentarium narrow, occupying about 1/6-1/5 the radius of corallites, and composed of coneentrical, herringbone or angular dissepiments. Tabulae incomplete, horizontally arched and slightly concave in middle part.
Remarks In the characters of tabulae this species is similar to Fomichevella orientalis (Stuckenberg), but in the latter, the corallites are smaller, the septa are slightly thickened in tabularium and are shorter and less in number.
Horizon and Locality Upper Carboniferous Guoyan Formation; Xintang, Panxian, Guizhou. Ivanovia xintangensis sp. nov. (Pl. I, figs. 4a, b)
Diagnosis Corallum compound, massive. Corallites connected with cystosa. Distance between two adjacent corallites about 6-11mm. Septal zone 5-6mm in diameter. Septa (15-18)+(15-18)in number, slightly tapering toward their ends: major ones occupying about 1/2 the radius of septal zone; minor ones sometimes undeveloped. Stereocolumella fusuliform, measuring 0.24×2.5,1.0×3.0, and 1.5×2.5mm in transverse and longitudinal diameters, sometimes connected with a major septum. Dissepiments herringbone or concentrical. Tabulae inclining toward inner part.
Remarks In morphology of stereocolumella, this species is similar to Ivanovia podolskiensis Dobrolyubova, but in the latter, the septa are shorter and thickened, the cystosa are more irregular and the sterocolumellae are larger.
Horizon and Locality Upper Carboniferous Weining Formation; Xintang, Panxian, Guizhou.
Kionophyllum xintangense sp. nov. (Pl. I, fig. 5a. b)
Diagnosis Corallite cylindrical, solitary, measuring 19-30mm in diameter. In the section of 19mm in diameter, peripheral part thickened. Septa 27+27 in number, pinnately arranged in cardinal quadrant, but radially arranged in counter quadrant; major ones not extending to the center of corallite; minor ones about 1/2 as long as the major ones. Peripheral cystosa undeveloped. Axial structure composed of a few septal lamellae and thickened medi an plate, forming a stereocolumella of about 3×5mm in diameter.
In the section of 30mm in diameter, peripheral cystosa developed. Septa 35+35 in number, radially arranged; major ones extending to the center of corallite; minor ones about 1/2 as long as the major ones; usually discontjnuously accreting in outer part. Axial part composed of 6-7 septal lamellae, a few tabellae and a thickened median plate, forming a weblike syncolumella of about 4×7mm in diameter. Tabulae concave and inclining toward inner part, transitionally developed with tabellae, with 6-7 of them occupying a space of 5mm.
Remarks In the pinnately arranged septa in cardinal quadrant in early stage, this species is similar to Kionophyllum yunnanense Wu et Zhao, but in the latter, the septa are less in number, the minor septa are longer and the axial structure is of the stereocolumella type in late stage.
Horizon and Locality Upper Carboniferous Guoyan Formation; Xintang, Panxian, Guizhou. Anfractophyllum ivanoviforme sp. nov. (Pl. I. figs. 6a, b)
Diagnosis Corallum compound, massive. Corallites conncted with brambly thecae in between which are densely arranged. Distance between two adiacent cotallites about 8-14mm. Cystosa irregular, usually small to medium in size, with septal spines. Septa usually of two orders and partly of three orders; major and minor ones (23-24)+(23-24)in number, tapering toward inner part, looing like a long pike; major ones almost extending to the cental part; minor ones slightly shortened; tertiary septa partly developed. Dissepiment concentrical or herringbone. Peripheral cystosa developed. Syncolumella composed of numerous septa lamellae, tabellae and indistinct median plates, measuring 1.0×2.5,1.5×1.5,1.5×3.0 and 2.5×3.0mm in diamters, usually connected with a major septa. Tabularium narrow, composed of tabulae inclining toward innerpart, with 9-10 of them occupying a space of 5mm.
Remarks In the corallites connected with cystosa in between, this species seems similar to Ivanovia, but in the brambly thecae, it is similar to Anfractophyllum. Since in Ivanovia, the brambly thecae are undeveloped, this species should belong to Anfractophyllum. By the character with the presence of a few brambly-thecae, this species is easily distinguished from other species of the genus.
Horizon and Locality Upper Carboniferous Guoyan Formation; Xintang, Panxian, Guizhou.
出处
《古生物学报》
CAS
CSCD
北大核心
1993年第6期765-772,820,共8页
Acta Palaeontologica Sinica
关键词
四射珊瑚
晚石炭世
珊瑚虫纲
rugose corals
Late Carboniferous
Panxian
Guizhou
