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Actinopterygian node G (characteristic of a possible clade uniting the redfieldiidae with the amphycentridae and dorypteridae): Branchiostegal rays are reduced in numbers.
The redfieldiid, amphicentrid and dorypterid families appear to have formed a clade through the Carboniferous, Permian and Triassic, characterised by the reduction of branchiostegal rays, in the gill region, from the primitive actinopterygian series composed of 12-13 elements to a single one in certain forms.
Modifications in the snout and orbit regions characterise the redfieliids, such as Redfieldius - above - known from the Late Triassic and Early Jurassic of North America. These fish were present worldwide in the Triassic, and are found particularly in the freshwater lakes of the Newark Supergroup (Late Triassic-Early Jurassic) of Eastern North America.