Size Variation of Conodonts During the Smithian–Spathian (Early Triassic) Global Warming Event
The Early Triassic Smithian–Spathian Boundary (SSB) crisis coincided with an episode of extreme warmth. A high-resolution stratigraphic framework comprising six conodont zones is provided in the Jiarong section, Nanpanjiang Basin, in South China. Detailed size measurements of 441 conodont elements of the closely related genera Neospathodus, Triassospathodus, and Novispathodus show for the first time that this clade suffered a temporary, but significant, size reduction during the SSB crisis. The size reduction of conodonts was probably caused by an episode of global warming.