Zhou, Z.r. (1984). 湘东南早二叠世栖霞期中、晚期的Staffella vulgaris(sp.nov.),Misellina claudiae及Parafusulina multiseptata(竹蜓)类群 - Middle and Late Chihshia (Permian) Fusulinids of southeastern Hunan. 古生物学报 - Acta Palaeontologica Sinica. 23(1): 107-123+153-156.

299949

Zhou, Z.r.

1984

23(1): 107-123+153-156

Publication

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The early Permain Chihsian fusulinids of Southeastern Hunan fall into four recognizable fusulinid zones and two subzones. The Schwagerina cushmani Zone is the lowest one which corresponds Darvasites cf. ordinatus Zone, the basal Surmaq Formation of Abadeh in Iran and the Chalaroschwagerina-Darvasites ordinatus Zone, the lower Dabalin Formation of Transcaucasia inthe USSR as discussed by the author (1982). All belonging to the middle and later Chihsia Stage,the other three zones Staffella vulgaris ( sp. nov.), Misellina claudiae and Parafusulina multiseptataZones are given below (in ascending order). The Staffella vulgaris Zone is of a low diversity in taxon, but of a great abundance in individual. It may further be subdivided into two subzones. The lower is the Staffella vulgaris subzone which contains some species of Staffellaand Nankinella embedded in black siliceous rockwith a thickness of 4-17 m. In terms of geogra-phical distribution, the subzone is consistent with the underlying Schwagerina cushmani Zone in Southeastern Hunan. A similar fusulinid assem-blage has been recorded in the basal Chihsia Formation of Houziguan of Ziyun County, Guizhou (Sheng, 1963) and the "Liangshan Member" of the Chihsia Formation on the Nanjin Hill of Jiangsu (Wang, 1978). Moreover, in the upperpart of the Trogkofel Formation on the Velebit Mountains of West Jugoslavia, a well-developed Staffella fauna occurs. The upper subzone is the Schwagerina baohetangensis (sp. nov.) subzone which contain several species of Schwagerina with a long shell preserved in black argillaceous limestone with a thickness of 0-16 m. From the geographical viewpoint, this subzone is limited as compared with the underlying subzone due to the lithological change towards the Longshan-Baimashan Uplift in Central Hunan. The Parafusulina multiseptata Zone, situated ovalis is the most common, is regarded as beingequivalent to the ammonoid Pseudohalorites Zone (Zhou, in press) near the Uplift in Central Hunan, considering the fact that grey biomicrites with chert concretions containing fusulinids transversely change into the black ammonoid-bearing mudstone with limestone lenticles. The Parafusulina multiseptata Zone, situated at the top of the Chihsia Formation and widely distributed in Southeast China is characterized by the presence of Parafusulina in association with Schwagerina chihsiaensis and S. chihsiaensis brevis. This zone consists of bioclastic limestone with a small amount of chert concretions and is believed to change into a series of black shalewith ammonoid Skaoyangoceras Zone in theabo-ve mentioned Uplift (Zhou, in press). The Pa-rafusulina multiseptata Zone and the coeval Sha-oyangoceras Zone are in a comformable contactwith the overlying black mudstone in which theammonoid Altudoceras-Paraceltites Zone (Zhou,in press )is recognized. A total of 22 species and 3 subspecies belonging to 6 genera are described in Chinese text.Among them 7 species and 2 subspecies are new and are briefly described here. Description of New Species Schwagerina baohetangensis sp. nov. (P1. II, figs. 1-2) Shell large, subcylindrical with somewhatpointed poles. Mature shell with 6-7 (1/2) volu-tions, 8.16-8.32 mm long, 1.83-2 mm wide;form ratio 4.2-4.5. Spirotheca thin with coarse alveolar structure especially in mature stage.Septa thin and loosely fluted, sometimes withsimple cuniculi. Axial fillings weak in the axialregion of inner volutions. Proloculus small androunded. The present form is similar to Schwagerina chihsiaensis (Lee) in the coiling of shell, the fluting of septa and the development of axial fillings, but differs from the latter in the elongatedlycylindrical shell, weaker development of axialfillings and thinner spirotheca and septa.Schwagerina quasibaohetangensis sp. nov. (P1. II, figs. 3-6) Shell medium to large in size, elongatedlyfusiform or irregular in form. Mature shell with5 (1/2)-7 volutions, 3.83-6.76 mm long, 1.55-1.85 mm wide; form ratio 1.55-1.86. The present species is similar to Schwagerina baohetangensis in the general characteristicsof shell, the thickness of spirotheca and septa,the developmental mode of axial fillings, but dif-fers from the latter in the irregular form of shelland the smaller form ratio. Schwagerina setumolia sp. nov. (P1. II, figs. 7-9) Shell large, cylindrical, with bluntly roundedpoles. Mature shell with 7 volutions, 9.3-10.16mm long, 2.12-2.37 mm wide; form ratio 4.1-4.6. Spirotheca thin with finer alveolar structure. Septa fluted regularly and intensively. Axialfillings weak. Proloculus rounded with outer di-ameter 0.14-0.2 mm. The present form is closely similar to Schwagerina serum Dunbar et Skinner in some res-pects but is distinguishable from the latter bythe smaller size and the shape of shell with lessvolutions, The present species is often found tobe associated with Schwagerina baohetangensis, it is easily separated from the latter by the thic-ker spirotheca and more intensely and regularlyfluted septa. Schwagerina laxoflucta sp. nov. (P1. II, figs. 11-12) Sehll large, fusiform. Mature shell with 7-7 1/2 volutions, 7.02mm long, 2.3 mm wide; form ratio 3.1. Septa regularly and loosely fluted; a few cuniculi seen in outer volutions. Axial fillings weak on the polar region of inner volutions.Proloculus rounded with thicker wall. The present form is distinguishable from Schwagerina setumolia by the smaller form ratio,more loosely coiled volutions, and broad androunded loops of Septa. Parafusulina tangtianensis sp. nov. (P1. III, figs. 1-3) Shell large, elongatedly fusiform with bluntly rounded poles. Mature shell with 6 1/2 volu-tions, 10.54 mm long, 3.11 mm wide; form ratio3.4. Septa regularly fluted. Axial fillings welldeveloped in inner 4-5 volutions. Proloculus large with outer diameter 0.45 mm. The present species is readily distinguishable from Parafusulina yunanica Sheng by the larger proloculus, loosely coiling of volutions, thinner spirotheca and well-developed axial fillings. Parafusulina tianzilingensis sp. nov. (P1. III, figs. 5-7) Shell large, fusiform with bluntly pointedpoles. Mature shell with 5-5 1/2 volutions,9-9.3 mm long, 2.74-2.94 mm wide; formratio 3.2-3.3. The present form is similar to Parafusulinatangtianensis in the general form of shell but can be separated from the latter by the high, narrow and slightly irregular fluting of septa andweak development of axial fillings. Parafusulina constrict brevis subsp, nov. (P1. IV, figs. 5-6) Shell large, subspherical in form with rounded poles. Mature shell with 6-6 1/2 volution,10.3 mm long, 3.15 mm wide; form ratio 3.2. The present subspecies can be distinguished from the Parafusulina constricta Chen by thelarge-sized shell and the larger form ratio. Staffslla vulgaris sp. nov. (P1. I, figs. 2-8) Shell large, discoidal in the first volution and lenticular in the next four volutions. Holotype specimen with 14 1/2 volutions, 5.37 mmlong, 5.82 mm wide; form ratio 0.92. Spirothecacomposed of two dark colored layers and a dia-phanotheca inbetween. Chomata well developed.Proloculus small with outer diameter 0.1 ram. The present form is similar to Staffella gigantea from Southwest China in some respectsbut is different from the latter by the larger sizeof shell, more developed chomata and apparently concave umbilical region. Staffella vulgaris longa sp. et subsp, nov. (P1. I, fig. 1) Shell the largest of the genus, with morethan 14 volutions, 7.2 mm long, 6.52 mm wide;form ratio 1.1. The present form differs from Staffella vul-garis in the larger size of shell and the larger format

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