Smithsonian.com

The original AMNH mount of Brontosaurus, reconstructed in 1905. Image from Wikipedia.

“Brontosaurus” should have disappeared a long time ago. Paleontologist Elmer Riggs recognized that the famous “thunder lizard” was a synonym of Apatosaurus more than a century ago, and a 1936 monograph by Charles Gilmore strongly reinforced what Riggs had discovered. Brontosaurus was not a real dinosaur. But, thanks to museum displays and pop culture persistence, Brontosaurus hung on. Even now, we feel compelled to invoke Brontosaurus in the same breath as Apatosaurus—it seems that no one can use the name Apatosaurus without explaining to their audience that we used to call the dinosaur Brontosaurus. No surprise, then, that the word use tracker Google Ngrams charts Brontosaurus as slightly more popular than Apatosaurus. We can’t let the dinosaur go.

Thanks to a fictional conceit, Brontosaurus recently received some screen time. Everybody knows that the plot of King Kong hinges on a gargantuan gorilla, but dinosaurs—stalwart holdovers from the Mesozoic—also have a role to play. What better way to show the power of Skull Island’s monstrous gorilla than to have him pummel a Tyrannosaurus? And when director Peter Jackson revitalized the story in 2005, he included a new and varied menagerie of modern dinosaurs, including a stampeding herd of Brontosaurus.

Jackson’s Brontosaurus looked just like the sauropods I encountered as a child. These computer-generated dinosaurs were drab, blunt-headed hulks that wallowed in swamps filled with soft plants. They were a throwback to a time when paleontologists thought of sauropods as dim-witted mountains of flesh. At the time the film’s fictional Skull Island expedition took place, this is exactly how good sauropods were thought to act.

The film’s official art book, The World of Kong: A Natural History of Skull Island, added another quirk to the dinosaur’s story. The film’s fictional Brontosaurus baxteri  is said to be capable of live birth. Instead of laying clutches of small eggs, gravid Brontosaurus females delivered between one and three large, live offspring at a time. This is not just an invention for the movie’s backstory, but something early 20th century paleontologists actually considered. Under the assumption that these dinosaurs spent most of their time in the water, where egg-laying would be impossible, paleontologist W.D. Matthew suggested that big sauropods may have given birth to live young. We now know this isn’t true, but at a time when huge sauropods were thought to have relied on swampy refuges, Matthew’s suggestion seemed to be a reasonable hypothesis.

Brontosaurus is here to stay. We love the dinosaur’s ghost too much to let it rest. And even though we won’t see digitally restored Brontosaurus stomping around in science documentaries, I’m glad King Kong used a bit of scientific license to bring my childhood favorite to life.