''Patrognathus'' is an extinct genus of

conodont Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, which ...

Use in stratigraphy

The

Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from Ma to Ma. It is preceded by the Famennian (the uppermost stage ...

, 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''

References

External links

* * Ozarkodinida genera Mississippian conodonts Tournaisian life Fossil taxa described in 1969 Mississippian first appearances Mississippian extinctions {{conodont-stub