1. (noun) any fish of the order Crossopterygii; most known only in fossil form

• crossopterygian
• lobe-finned fish

1. (noun) any fish of the order Crossopterygii; most known only in fossil form

• bony fish

1. (noun) any fish of the order Crossopterygii; most known only in fossil form

• coelacanth
• latimeria chalumnae

1. (noun) any fish of the order Crossopterygii; most known only in fossil form

• crossopterygii
• subclass crossopterygii