Acanthodii

plural noun

Ac·​an·​tho·​dii

ˌaˌkanˈthōdēˌī,

ˌakən-

: a subclass of Placodermi comprising primitive Paleozoic fishes having the anterior margin of each fin supported by a stout spine and often having one or more pairs of spines similar to the fin spines along the lower lateral part of the body between the paired fins of each side

Word History

Etymology

New Latin, from Acanthodes

First Known Use

1851, in the meaning defined above

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