There are many challenges that face those writing the lyrics to operas, but figuring out what can rhyme with dinosaur names isn’t often one of them. But wrangling multisyllabic, Latin- and Greek-derived names of prehistoric creatures into verse was an integral part of Eric Einhorn’s job as the librettist behind Rhoda and the Fossil Hunt, a new, family-friendly opera currently running at the American Museum of Natural History in New York City.

Created by On Site Opera, which puts on operas in unusual places (like Madame Tussauds Wax Museum) across New York City, in conjunction with the Lyric Opera of Chicago and the Pittsburgh Opera, Rhoda and the Fossil Hunt follows the true story of Rhoda Knight and her grandfather, the famous paleoartist Charles R. Knight.

Knight worked as a freelance artist for the American Museum of Natural History from 1896 until his death in 1953, creating images of extinct species that paved the way for how we imagine dinosaurs even now. He studied with taxidermists and paleontology experts and was one of the first to paint dinosaurs as flesh-and-blood creatures in natural habitats rather than fantastical monsters, studying their bones and creating sculptural models to make his renderings as accurate as contemporary science made possible.

In the 20-minute opera, singers move around the museum’s Hall of Saurischian Dinosaurs, performing among skeletons and even some paintings by Knight himself. Einhorn, who also serves as the director of On Site Opera and stage director for the opera, wrote the libretto based on stories about the real-life Rhoda—who now goes by Rhoda Knight Kalt—whom he met with frequently during the development process.

AMNH // R. Mickens

“I spent a lot of time with Rhoda just talking about her childhood,” he tells Mental Floss, gathering anecdotes that could be worked into the opera. “She tells this great story of being in the museum when they were unpacking the wooly mammoth,” he says. "And she was just there, because her grandfather was there. It's being at the foot of greatness and not even realizing it until later.”

But there was one aspect of Rhoda’s childhood that proved to be a challenge in terms of turning her story into a performance. “Unfortunately, she was a really well-behaved kid,” Einhorn says. “And that doesn't really make for a good opera.”

Knight Kalt, who attended the opera’s dress rehearsal, explains that she knew at the time that if she misbehaved, she wouldn’t be allowed back. “I knew that the only way I could be with my grandfather was if I was very quiet,” she says. “Sometimes he would stand for an hour and a half discussing a fossil bone and how he could bring that alive … if I had interrupted then I couldn't meet him [at the museum anymore].”

In the fictionalized version of Knight Kalt's childhood (which takes place when Rhoda is 8), Rhoda looks around the museum for the missing bones of the dinosaur Deinocheirus so that her grandfather can draw them. The Late Cretaceous dino, first discovered in 1965, almost didn't make it into the show, though. In the first draft of the libretto, the dinosaur Rhoda is searching for in the museum was a relatively new dinosaur species found in China and first unveiled in 2015—Zhenyuanlong suni—but the five-syllable name proved impossible to rhyme or sing.

Rhoda Knight KaltShaunacy Ferro

But Einhorn wanted to feature a real dinosaur discovery in the opera. A paleontologist at the museum, Carl Mehling, suggested Deinocheirus. “There are two arms hanging right over there,” Einhorn says, gesturing across the Hall of Saurischian Dinosaurs, “and until [recently] the arms were the only things that had ever been discovered about Deinocheirus.” Tying the opera back to an actual specimen in the museum—one only a few feet away from where the opera would be staged—opened up a whole new set of possibilities, both lyrically and otherwise. “Once we ironed that out, we knew we had good science and better rhyming words.”

As for Knight Kalt, she says the experience of watching her childhood unfold in operatic form was a little weird. “The whole story makes me laugh,” she says. But it was also a perfectly appropriate way to honor her grandfather. “He used to sing while he was painting,” she says. “He loved the opera.”

Rhoda and the Fossil Hunt will be performed at the American Museum of Natural History on Fridays, Saturdays, and Sundays until October 15. Performances are free with museum admission, but require a reservation. The opera will later travel to the Lyric Opera of Chicago and the Pittsburgh Opera.