古生物学报
古生物學報
고생물학보
ATCA PALAEONTOLOGICA SINICA
2001年
2期
239-243
,共5页
旋壁超微构造%古纺锤%Palaeofusulininae亚科
鏇壁超微構造%古紡錘%Palaeofusulininae亞科
선벽초미구조%고방추%Palaeofusulininae아과
电子显微镜下研究表明,Palaeofusulina的旋壁由致密层及“透明层”组成,“透明层”的晶粒形状、大小和排列方式与旋壁四层式(Fusulinella型)中的透明层超微特征有较大的差异。文中应用Palaeofusulina旋壁的透明层一词,加以引号,以示两者之间的区别。晚二叠世长兴阶的Palaeofusulina属及其旋壁构造相同的若干属均可归于Palaeofusulininae M.-Maclay, 1963亚科。
電子顯微鏡下研究錶明,Palaeofusulina的鏇壁由緻密層及“透明層”組成,“透明層”的晶粒形狀、大小和排列方式與鏇壁四層式(Fusulinella型)中的透明層超微特徵有較大的差異。文中應用Palaeofusulina鏇壁的透明層一詞,加以引號,以示兩者之間的區彆。晚二疊世長興階的Palaeofusulina屬及其鏇壁構造相同的若榦屬均可歸于Palaeofusulininae M.-Maclay, 1963亞科。
전자현미경하연구표명,Palaeofusulina적선벽유치밀층급“투명층”조성,“투명층”적정립형상、대소화배렬방식여선벽사층식(Fusulinella형)중적투명층초미특정유교대적차이。문중응용Palaeofusulina선벽적투명층일사,가이인호,이시량자지간적구별。만이첩세장흥계적Palaeofusulina속급기선벽구조상동적약간속균가귀우Palaeofusulininae M.-Maclay, 1963아과。
Deprat J. established the genus Palaeofusulina in 1912, and the type species Palaeofusulina prisca Deprat 1913 was described in the next year. In his description the spirotheca was said to be composed of a tectum and a keriotheca. His illustrations seeminly are a combination of photographs, retouched photographs, and line-drawing. In some illustrations, including the holotype, obvious retouching of a photograph has produced rather abnormal structural features. The spirotheca of Palaeofusulina, according to Sheng Jing-Zhang (1955), is composed of two layers, a tectum and a diaphanotheca. The genus Palaeofusulina is restricted to the Changhsing stage of latest Permian, which is referred to the fusulinid faunal zone of Palaeofusulina (Sheng, 1955, p.289).
Palaeofusulina is the most typical genus of fusulinid foraminifers with a two-layered spirotheca, which is commonly referred to the Palaeofusulina-type of spirotheca (Sheng et al.,1988,p.13). The SEM study has revealed that the tectum, with a thickness varying from 2-2.5 μm,is composed of isometric crystal granules with a diameter generally smaller than 1.0μm, showing no preferred orientation in their arragement. Our SEM examination has shown that the diaphanotheca is 16-20μm thick and is composed of two groups of crystal granules, one group is roughly isometric crystal granules with a diameter about 1.5-2μm, and the group is represented by a series of crystal granules (3-4μm) with a regular shape. The ultrastructural features of the diaphanotheca in the test wall of Palaeofusulina can be distinguished from the diaphanotheca of the Fusulinella-type by its two groups of crystal granules.
The genus Palaeofusulina was originally described by A.M.-Maclay (1963,p.228) as an indepedent genus of the subfamily Palaeofusulininae. To date,the following genera have been assigned to this subfamily: Palaeofusulina Deprat, 1912 (Shindella Chedija, 1984), Dunbarula Ciry, 1948 (Paradunbarula Skinner, 1969, Nanlingella Rui et Sheng, 1981, Parananlingella Rui et Sheng, 1981, Pseudodunbarula Chedija, 1984), Gallowayinella Chen, 1934, Tewoella Sun 1979 (Ziguiella Lin, 1980) and Codonofusiella Dunbar et Skinner, 1937.