elytra (n.)youdaoicibaDictYouDict[elytra 词源字典]
1774, plural of elytron "hardened wing of an insect," from Greek elytron "sheath," from elyein "to roll round," from PIE root *wel- (3) "to turn, roll," with derivatives referring to curved, enclosing objects (see volvox). Related: Elytroid.[elytra etymology, elytra origin, 英语词源]