Polygnathus is an extinct genus of conodonts.

• †Polygnathus acrinodosus Aboussalam 2003
• †Polygnathus alkhovikovae Baranov, Slavík & Blodgett 2014
• †Polygnathus angustipennatus Bischoff and Ziegler 1957
• †Polygnathus aragonensis Martínez-Pérez & Valenzuela-Ríos 2014
• †Polygnathus arthuri Baranov, Slavík & Blodgett 2014
• †Polygnathus bardashevi Baranov, Slavík & Blodgett 2014
• †Polygnathus bicristatus Mossoni et al. 2015
• †Polygnathus burretti Savage 2013
• †Polygnathus chongqingensis Wang in Gong et al. 2012
• †Polygnathus carlsi Martínez-Pérez & Valenzuela-Ríos 2014
• †Polygnathus communis
  • †Polygnathus communis hanensis Savage 2013
  • †Polygnathus communis longanensis Qie et al. 2014
  • †Polygnathus communis namdipensis Savage 2013
  • †Polygnathus communis phaphaensis Savage 2013
• †Polygnathus costatus Klapper 1971
  • †Polygnathus costatus partitus
• †Polygnathus crassulus
  • †Polygnathus crassulus salapensis Savage 2013
• †Polygnathus damelei Vodrazkova et al. 2011
• †Polygnathus dujieensis Qie et al. 2014
• †Polygnathus efimovae Kononova et al. 1996
• †Polygnathus extralobatus phoensis Savage 2013
• †Polygnathus hemiansatus
• †Polygnathus hemipennatus Aboussalam 2003
• †Polygnathus hojedki Gholamalian et al. 2013
• †Polygnathus holynensis Vodrazkova et al. 2011
• †Polygnathus housei Aboussalam 2003
• †Polygnathus ivanowskyii Baranov, Slavík & Blodgett 2014
• †Polygnathus karsteni Baranov, Slavík & Blodgett 2014
• †Polygnathus kitabicus
• †Polygnathus lezhoevi Baranov, Slavík & Blodgett 2014
• †Polygnathus ilmenensis Zhuravlev 2003
• †Polygnathus linguiformis Hinde^[1]
• †Polygnathus michaelmurphyi Baranov, Slavík & Blodgett 2014
• †Polygnathus nuragicus Mossoni et al. 2015
• †Polygnathus peltatus Yuan & Sun 2023
• †Polygnathus pollocki Druce 1976
• †Polygnathus postvogesi Plotitsyn & Zhuravlev 2017
• †Polygnathus praeinversus Lu et al. 2018
• †Polygnathus pseudocommunis Wang et al. 2016
• †Polygnathus pseudocostatus Klapper & Vodrážková 2013
• †Polygnathus ramoni Martínez-Pérez & Valenzuela-Ríos 2014
• †Polygnathus robertensis Vodrazkova et al. 2011
• †Polygnathus rossicus Zhuravlev 2000
• †Polygnathus salixensis Vodrazkova et al. 2011
• †Polygnathus settedabanicus Baranov, Slavík & Blodgett 2014
• †Polygnathus sharyuensis Ovnatanova et al. 2019
• †Polygnathus varcus Stauffer 1940
• †Polygnathus wapanuckensis Harlton 1933
• †Polygnathus yakutensis Baranov, Slavík & Blodgett 2014

The Tournaisian, the oldest age of the Mississippian (also known as Lower Carboniferous), contains eight conodont biozones, one of which is defined by a Polygnathus species:

• the zone of Gnathodus pseudosemiglaber and Scaliognathus anchoralis
• the zone of Gnathodus semiglaber and Polygnathus communis
• the zone of Dollymae bouckaerti
• the zone of Gnathodus typicus and Siphonodella isosticha
• 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

• List of Global Boundary Stratotype Sections and Points

• "Polygnathus". The Encyclopedia of Life.
• Polygnathus at fossilworks.org (retrieved 1 May 2016)