Cheirolepis trailli ('classic specimen', Agassiz 1835; Pearson and Westoll 1979; Middle Devonian, 390 mya; 30-55 cm in length) is considered one of the earliest actinopterygian (ray-finned) fish with 'standard' dermal skull bones. The purported poroloepiform, Quebecius is a descendant.

In Cheirolepis, the orbit is far forward. The jaws opened at right angles to form a large gape. The pineal opening pierces the interfrontal. Bony gill covers are present. The pectoral fins are lobed and muscular, but the hind fins are not and shifted forward. The pelvis and the single dorsal fin is large and broad-based. The tail is heterocercal.

Another purported Cheirolepis specimen nests with Leptolepis.