Journal of Geology & Geophysics
Open Access

The descendants Clarkina of the Eurasian stock (Changhsingian) and the forms of Clarkina wangi at Ganxi, Xiakou and Tianqiao sections, South China

International Conference on Geology

June 22-23, 2015 Florida, USA

Mutwakil Nafi Fadil Elmula 1,3, Muna El Dawi2, Xia Wenchen3 and Zhang Ning3

Scientific Tracks Abstracts: J Geol Geosci

Abstract :

The descendants Clarkina of the Eurasian stock (Changhsingian) are composed of C. changxingensis, C. changxingensis yini, C. deflecta, C. guangyuanensis, C. inflecta, C. iranica, C. liangshanensis, Clarkina longicuspidata, C. meishanensis meishanensis, C. meishanensis, C. orientalis, C. parasubcarinata, C. postwangi, C. prechangxingensis and C. predeflecta, C. preiranica sp. nov., C. subcarinata (Sweet), and C. wangi. One new species of C. preiranica sp. nov. has been recognized. Clarkina preiranica sp. nov. is very important because it is found at the same level with C. wangi. The base of the Changhsingian can be defined within an evolutionary lineage from C. longicuspidata to C. wangi based on a refined taxonomic approach. There are three forms of Clarkina wangi: (1) Those forms characterized by drop-like, with a short and wide platform, usually no free blade, fused carina looks like a high wall and reaching beyond the posterior margin., (2) Those forms characterized by a free blade, platform lenticular in outline, fused carina looks like a high wall and reaching beyond the posterior margin., (3) Those forms with high and highly fused posterior carina, which does not reach beyond the posterior margin. The base of the Changhsingian has been suggested as the first appearance datum (FAD) of Clarkina wangi which characterized by drop-like, with a short and wide platform, usually no free blade; fused carina looks like a high wall and reaching beyond the posterior margin.

Biography :

Mutwakil Nafi Fadil Elmula has completed his MSc from University of Khartoum, Sudan and Ph.D. in Petroleum Geology diagenesis from China University of Geosciences and postdoctoral (Micropaleontology-conodont) studies from China University of Geosciences. He is Associate Professor at Dongola University, Faculty of Earth Sciences and Mining, Department of petroleum Geology, Sudan. He has published more than 20 papers in reputed journals and has been serving as an editorial board member of European Journal of Scientific Research. He is a member of SCS (Subcommission on Carboniferous Stratigraphy) and SPS (Subcommission on Permian Stratigraphy).