The anterior of three principal cartilages which primitively comprise the base of each pectoral and pelvic fin in cartilaginous fishes (though in later forms often modified or absent, especially in the pelvic fin). Also: the corresponding structure in embryonic (and certain primitive adult) bony fishes. Compare mesopterygium , metapterygium .
Late 19th century; earliest use found in Thomas Huxley (1825–1895), biologist and science educationist. From German Propterygium from pro- + ancient Greek πτερύγιον. Compare slightly earlier propterygial.