A Discussion of the Early Reported Species of Clarkina (Permian Conodonta) and the Possible Origin of the Genus

Bruce R. Wardlaw and Mei Shilong

pp. 33-52, 7 plates, in English

Abstract:

The early reported species of Clarkina are derived from three separate stocks and can be easily differentiated. The species bitteri was probably derived from Mesogondolella phosphoriensis and is placed in the new genus Pseudoclarkina. The species wilcoxi evolved from bitteri and is also placed in Pseudoclarkina. The species altudaensis is derived from Jinogondolella shannoni, retains relict to prominent serrations, and is placed in Jinogondolella. The species crofti is probably derived from Jinogondolella denticulata (not J. altudaensis), appears to be transitional to the first Clarkina species (C. postbitteri) found in objective succession in China and is placed in Protoclarkina.

Keywords: Permian, conodont, origin