The release of Jurassic Park in 3-D provoked fresh curiosity about “Where did they get T-rex’s roar”?

If you think the director of a science fiction movie should have compiled it from recordings of Harlan Ellison crushing a heckler, Teresa Nielsen Hayden disemvowelling a wayward commenter, and John Scalzi pounding home the mallet of loving correction, there’s just one problem — most of those sounds, like much of the web itself, had yet to be created when Jurassic Park came out in 1993.

Instead, The Making of Jurassic Park says the T. rex’s roar combined a baby elephant’s squeal, an alligator’s gurgling, and a tiger’s snarl. Its breath was the sound of air escaping a whale’s blowhole.

And it probably was. At least there seems to be no disagreement, unlike the many explanations of Tarzan’s yell. My favorite holds that an opera singer’s vocalization was blended with “the growl of a dog, a trill sung by a soprano, a note played on a violin’s G string and the howl of a hyena recorded backward.” But that’s not true.