Idiognathodus

Idiognathodus is an extinct conodont genus in the family Idiognathodontidae.

Use in stratigraphy
The species Idiognathodus simulator made its first appearance during the Gzhelian, the youngest age of the Pennsylvanian (late Carboniferous).

Two species (Idiognathodus toretzianus and Idiognathodus sagittatus) are amongst the three conodonts forming the biozones of the Kasimovian, the third stage in the Pennsylvanian.

One species (Idiognathodus sinuosus) is an index fossil of a biozone of the Bashkirian, the oldest age of the Pennsylvanian, amongst six biozones based on conodonts.