If in your idle moments you sometimes find yourself staring at pelicans through plane windows while humming John Williams’s Jurassic Park theme song and dreaming about someday cozying up to your very own T. rex, bad news: Science now says it ain’t gonna happen.

A bunch of palaeogeneticist party poopers at the University of Copenhagen and Australia’s University of Perth took a good hard look at the leg bones of some moa, a.k.a. giant extinct birds, comparing their ages and the degrees of DNA degradation, by which they mean—as I understand it (and I’m not at all sure I do)—the rates at which the molecular bonds between the nucleotides in the DNA unravel, and thus become unreproducible. Even under the best possible preservation conditions, they determined that DNA has a half-life of a mere 521 years. That means by year 521 postmortem, only half the bonds would still be holding; at the end of another 521 years, only half of the remaining bonds would still be intact. (Math/science types: Kindly append corrections in the comments below.) At that rate, by the end of a mere 1.5 million years, the DNA strands would be too short to contain recoverable—and reproducible—information, and in 6.8 million years, they’d all be gone. As in, no mo moa.

Since the Great Dinosaur Die-Off occurred some 65 million years ago, there just isn’t any dino DNA out there to be had. No, not even preserved in amber. So, no T. rex, and no raptors, and no amusement park. The music, however, remains.