What is "idiognathoides"

Idiognathoides is an extinct genus of conodonts.

Glen K. Merrill stated in 1963 that "conodont workers have considered Idiognathoides to be a junior synonym of Polygnathodella but it now proves to be a junior synonym of Cavusgnathus. Polygnathodella and Cavusgnathus are shown to form a transitional series."