Actinistia
plural noun
Ac·ti·nis·tia
ˌak-tə-ˈni-stē-ə
: an order (superorder Crossopterygii) of chiefly Mesozoic fishes including the family Coelacanthidae having the interspinous bones supporting each dorsal and anal fin fused into one piece compare latimeria
Word History
Etymology
New Latin, from actin- + -istia (from Greek histion web, cloth, sail); akin to Greek histos mast, weaver's beam, web
First Known Use
1871, in the meaning defined above