cros·​sop·​ter·​yg·​ian ˌkrȯ-ˌsäp-tə-ˈri-j(ē-)ən How to pronounce crossopterygian (audio)
: any of a subclass (Crossopterygii) of bony fishes (such as a coelacanth) that have paired fins suggesting limbs, that may be ancestral to the terrestrial vertebrates, and that are mostly extinct

called also lobe-fin

crossopterygian adjective

Word History


New Latin Crossopterygii, subclass name, from Greek krossoi fringe + pterygion, diminutive of pteryg-, pteryx wing, fin; akin to Greek pteron wing — more at feather

First Known Use

1861, in the meaning defined above

Time Traveler
The first known use of crossopterygian was in 1861

Dictionary Entries Near crossopterygian

Cite this Entry

“Crossopterygian.” Dictionary, Merriam-Webster, Accessed 19 Apr. 2024.

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