Streptognathodus isolatus new species (Conodonta): Proposed index for the Carboniferous-Permian boundary

Davydov et al. (1995) recently proposed the Aidaralash Creek section in northern Kazakhstan (Figures 2 and 3) as the Global Stratotype Section and Point (GSSP) for the base of the Permian System. The proposed boundary is the level in an evolutionary sequence where Streptognathodus wabaunsensis Gunnell gives rise to a descendent with an isolated node field on the inside of the upper platform surface. This morphotype constitutes a new and distinct species for which we propose the name Streptognathodus isolatus new species.