Patrognathus

Patrognathus is an extinct genus of conodonts.

Use in stratigraphy
The Tournaisian, the oldest age of the Mississippian (also known as Lower Carboniferous) contains eight conodont biozones, four of which contain Patrognathus species:
 * the zone of Siphonodella quadruplicata and Patrognathus andersoni (upper zone of Patrognathus andersoni)
 * the lower zone of Patrognathus andersoni
 * the zone of Patrognathus variabilis
 * the zone of Patrognathus crassus