[kro-sop-tuh-rij-ee-uh
n] 
| 1. | any fish of the group Crossopterygii, extinct except for the coelacanth, regarded as being ancestral to amphibians and other land vertebrates. |
| 2. | pertaining to or resembling a crossopterygian. |
| cros·sop·te·ryg·i·an (krŏ-sŏp'tə-rĭj'ē-ən) n. See lobe-finned fish. [From New Latin Crossopterygiī, group name : Greek krossoi, fringe (from krossōtos, fringed, from krossai, projecting stone blocks) + Greek pterugia, fins, pl. diminutive of pterux, pterug-, wing; see pterygoid.] cros·sop'te·ryg'i·an adj. |
| lobe-finned fish (lōb'fĭnd') n. A member of the subclass Crossopterygii, a group of bony fishes with paired rounded fins, suggesting limbs, that are extinct except for the coelacanths. The lobe-finned fishes are regarded by some as ancestors of amphibians and other terrestrial vertebrates. Also called crossopterygian, lobefin. |
crossopterygian
any member of the subclass Crossopterygii, a group of primitive, lobe-finned, bony fishes believed to have given rise to the amphibians and all other land vertebrates. They appeared at the beginning of the Devonian Period (395,000,000 years ago) but are now represented only by the coelacanth (Latimeria chalumnae).
Learn more about crossopterygian with a free trial on Britannica.com.
