any bony fish of the subclass Crossopterygii, having fleshy limblike pectoral fins. The group, now mostly extinct, contains the ancestors of the amphibians
See also coelacanth
adjective
2.
of, relating to, or belonging to the Crossopterygii
Word origin
C19: from New Latin Crossopterygiī, from Greek krossoi fringe, tassels + pterugion a little wing, from pterux wing
crossopterygian in American English
(krəˌsɑptəˈrɪdʒiən; krɑˌsɑptəˈrɪdʒiən)
noun
any coelacanth: thought to be the precursors of amphibians
Word origin
< ModL Crossopterygii, name of the group (< Gr krossoi, fringe + pteryx, fin, wing: see pterygoid) + -an