【摘要】 本文描记甘肃靖远磁窑地区臭牛沟组的介形类化石,计21属32种(其中1新属、19新种、2未定种),并建立Microcheilinella-Prtjpbaordoa-Healdianella-Grobrpcpmcja介形类组合。根据组合特征及其与国内外对比,将臭牛沟组的时代定为早石炭世。更多还原

【Abstract】 The Early Carboniferous strata in Ciyao district of Jingyuan county can be divided from bottom to top into the Qianheishan Formation, the Chouniukou Formation, and the Yushuliang Formation. The ostracodes described in this article are collected from the Chouniukou Formation and are represented by the Microcheilinella-Orthobairdia-Healdianella-Cribroconcha assemblage, with 32 species in 21 genera (including 1 new genus, 19 new species and 2 undetermined species), namely, Kindella illustra sp. nov., Scrobicula foveolata Zanina, Oliganisus unicostatus sp. nov., Uchtovia definita sp. nov., Knoxina (Paraknoxina) sublecta sp. nov., Knoxiella normalis Shi et Z. W. Li, Sansabella whitei Bradfield, Shivaella macallisteri Sohn, S. suppetia Sohn, Bairdia yushuliangensis sp. nov., Cryptobairdia subnitida (Shi), Orthobairdia squalida sp. nov., O. oklahomaensis(Harlton), O. daishuigouensis sp. nov., O. xiaogouensis sp. nov., Healdia vinitaensis Harlton, Cribroconcha jingyuanensis Shi et Z. W. Li, C. singula sp. nov., Healdianella incerta sp. nov., H. renalata sp. nov., Cytherellina? sp., Pseudobythocypris lunata sp. nov., Pseudobythocypris sp., Cavellina xibeiensis sp. nov., Sulcella nitela sp. nov., Alatacavellina parva sp. nov., Microcheilinella bella sp. nov., M. obesa Cooper, M. ciyaoensis sp. nov., M. unispinosa Cooper, M. incompata sp. nov. and Longyuanella valida gen. et sp. nov.Description of New GenusFamily UncertainGenus Longyuanella Z. W. Li gen. nov.Type species Longyuanella valida Z. W. Li gen. et sp. nov.Diagnosis Carapace subovate in lateral view, Dorsal border arched; ventral border nearly straight; both ends rounded. Right valve larger, overlapping left one along free margin. Surface ornamented with concentric-lines visible in the core; concentric-lines clearer in posterior part than in anterior part. Muscle scar and hingement not clear.Heteromorphs Dorsal margin of right valve obviously higher than that of left one, with the highest point in middle part. In dorsal view both sides strongly convex, close to oval, with the thickest point in posterior part.Tecnomorphs Highest point at 1/3 of anterior part, elongate-elliptical in dorsal view, with the thickest point in the middle part.Remarks This new genus is similar to Barychilina Ulrich(1891)and Endolophia Kesling (1954) in the outline of its lateral view, in its surface decoration, and in the larger size of its right valve. However, it differs from Barychilina in the absence of pits and from Endolophia in the absence of the ridge on the inner side of the wall.Because the muscle scars are not distinct, the family can not be determined for the time being.Distribution and Range Gansu, Early Carboniferous.更多还原