From Season Devereux this morning, this excellent image on Threads, from the poster linguisticdiscovery:
Two flying entities, the helicopter and the pterodactyl, are about to hybridize, to merge into a single thing, which will then obviously be denoted by the portmanteau helicopterodactyl — Is it a plane? (not exactly, though it’s a kind of aircraft) Is it a bird? (not exactly, though it has wings) It’s Superfly!
The poster, however, was interested not in hybridization, but in the etymology of helicopter. Their comment:
PSA: The pter in pterodactyl is the same pter in helicopter
Yes, that’s right: helicopter is actually helico + pter, not heli + copter
Ancient Greek: hélix ‘something twisted or spiraling’, pterón ‘wing’
And so it is. Though the popular analysis heli + copter isn’t crazy; it’s a result of copter having been created as a clipping of helicopter — shorter is better, and as phonological abbreviations of longer forms, clippings have no reason to respect the etymological boundaries of elements (they aren’t respected in, for instance, robot > bot, alligator > gator, cigar > gar).
Then, once you’ve got the new item copter, it’s available to combine with other words, as in the compound copter patrol (as first element) and a number of compounds with copter as second element:
fire copter / firecopter ‘helicopter used to fight fires’
news copter / newscopter ‘helicopter used to gather footage for tv news’
Rocket Copter — “Rocket Copters launch like rockets and fly like helicopters, producing a dazzling spinning light show with ultra-bright LED lights that are visible night or day” (ad for the toy, here)