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Actinopterygian node J: The skull's ethmoid region is lengthened, elongated ascending process of the parasphenoid.
Actinopterygian node K (defining node of the "CHONDROSTEI"): Palatoquadrate bones meet anteriorly in midline, large and blade shaped hyomandibular, absence of suborbital bones, reduced or absent preopercular, opercular and gulars, reduced body scales, peg and socket articulation generally absent from dermal scutes.
The paddlefish form the third clade generally considered as belonging to the "chondrosteans". These include extant forms of up to two metres in length, which feed on plankton, and appear to be related to both sturgeons and Jurassic chondrosteids.