†family Petraiidae de Koninck 1872 (horn coral)
Anthozoa - Stauriida - Petraiidae
Parent taxon: Metriophyllina according to D. Hill 1981
See also Hill 1956
Sister taxa: Combophyllidae, Cyathaxoniidae, Famaxonia, Gymnophyllum, Hadrophyllidae, Kielcephyllidae, Laccophyllidae, Lindstroemiidae, Lyliophyllum, Metriophyllidae, Rhipidophyllum, Ridderia
Subtaxa: Haptophyllum Petraia Petraiella Protozaphrentis
Ecology: stationary epifaunal suspension feeder
Distribution:
• Devonian of Australia (1 collection)
• Silurian to Devonian of Austria (1)
• Silurian of United States (1: Oklahoma)
• Ordovician of the United Kingdom (3)
Total: 6 collections each including a single occurrence