Crossopterygii

plural noun

Cros·​sop·​te·​ryg·​ii

1

: a superorder of Choanichthyes comprising the lobe-finned fishes that have existed since the Devonian but are now largely extinct, that have paired fins somewhat resembling limbs with a scaly axis fringed on one or both sides by dermal rays, and that are generalized fishes in some respects resembling elasmobranchs and in others foreshadowing terrestrial vertebrates which may have evolved from unknown early members of the group compare latimeria

2

in some classifications : a division of fishes coextensive with Choanichthyes or comprising Choanichthyes together with Cladistia compare actinistia , rhipidistia

Word History

Etymology

New Latin, from cross- + -pterygii

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!