Triassospathodus aff. symmetricus (Orchard, 1995)

Figs. 18G; 24B, E, F

2004 Neospathodus sp. aff. N. symmetricus Orchard; Koike, p. 133, figs. 2.4–2.5.

2015 Triassospathodus symmetricus (Orchard); Chen et al., fig. 8.1.

Number of specimens.> 20.

Remarks. Te biostratigraphical range of these specimens is usually slightly older than that of Tr. symmetricus . Te P 1 element of Tr. aff. symmetricus resembles that of Tr. symmetricus, but is shorter with fewer denticles and a more circular and larger outline of the basal cavity. Te denticles are less inclined posteriorly compared to Tr. symmetricus and often have one additional small posteriormost denticle. Its denticles are not posteriorly arched as in Nv. pingdingshanensis . It differs from the very similar Nv. abruptus by having a downturned posterior part and posteriorly reclined denticles. Tis species might represent a transitional form between Novispathodus abruptus and Triassospathodus symmetricus but a multi-element apparatus reconstruction is currently lacking.

Occurrence. Taho Formation, Southwest Japan, Spathian age (Koike, 2004); South China, Luolou Formation, at the top of the black shales and the base of the nodular limestone in the earliest Spathian (this study).