摘要
湘中地区船山组含丰富的四射珊瑚化石,主要为地方性分子,其发展具有明显的阶段性:下部主要为单体双带型珊瑚及互嵌状复体珊瑚;中部以单体三带型珊瑚和Kepingophyllidae科的原始分子繁衍为特征;而在上部,Kepingophyllidae科的进化分子非常繁盛,并出现了一些早二叠世的分子,如Vesotabularia,Lonsdaleiastraea。这些阶段性的变化对揭示石炭纪和二叠纪四射珊瑚的演化具有重要意义。 笔者在船山组中上部建立了两个四射珊瑚组合,自下而上为:(1)Eokepingophyllum-Qinglongshanophyllum组合; (2)Kepingophyllum-Parawentzellophyllum组合。此外,描述1新属Paraivanovia及10新种。
The rugose corals are abundant in the Chuanshan Formation of Central Hunan, among them the endemic genera and species are dominant.
The Chuanshan Formation can be divided into three parts: In the lower part, solitary, double zoned rugose corals and aphroid compound rugose corals are predominant; The middle part is characterized by yielding abuadant solitary, triple zoned rugose corals and original genera of Kepingophyllidae, while in the upper part, the advanced genera of Kepingophyllidae are dominant. It is worth to point out that some early Permian rugose corals, such as Vesotabularia, Lonsaleistraea may be present in the upper part of the Chaanshan Formation.
These peridic changes of the rugose corals in the Chuanshan Formation are very important to reveal the evolutional relation of the rugose corals of the Carboniferous and the Permian.
The rugose corals of the Chuanshan Formation may be subdivided into two assemblages in ascending order as follows:
(1) Eokepingophyllum-Qingtongshanophyllum assemblage;
(2) Kepingophyllum-Parawentzellopyllum assemblage.
New genus Paraivanovia and 10 new species are described.
Description of new genus Paraivanovia (gen. nov.)
Description: Aphroid, with traces of strato-theca or brambly-theca; minor septa are present, axial column with variable medial plate; with very rare radial lamellae, or without lamellae; with more conical tabellae; dissepiments which constitute wide dissepimentarium are small and nearly plate; tabulae continuous and sagging; with some periphyeral clinotabellae.
Type species: Paraivanovia regularis (gen. et sp. nov)
Discussion: This new genus can be distinguished from the similar and closely related genus Ivanovia by the simple and compact axial structure of Ivanovia.
Paraivanovia (gen. nov.) is different from Vesotabularia, because there aren't traces of strato-theca or brambly-theca in Vesotabularia with more radial lamellae.
Horizon ang Locality: Upper part of the Chuanshan Formation; Lian yuan County,Hunan Province.
出处
《现代地质》
CAS
CSCD
1990年第1期35-45,T002,T003,共13页
Geoscience
