After spending more than a century dismissed as a mislabeled Apatosaurus, Brontosaurus may be getting its identity back.
The long-necked dinosaur deserves a genus distinct from that of Apatosaurus, a team of European paleontologists report April 7 in PeerJ. Two other dinosaurs classified under Apatosaurus should also migrate to the Brontosaurus genus, the researchers determined after reviewing all the members of the Diplodocidae family of dinosaurs.
The original Brontosaurus excelsus (meaning “thunder lizard”) was named in 1879. But in 1903, paleontologists decided that Brontosaurus excelsus was so similar to species in the Apatosaurus genus that it belonged there as well.
Brontosaurus was renamed Apatosaurus excelsus, but the thunder lizard lingered in the public eye. The curator of the American Museum of Natural History did not update the label for its Brontosaurus skeleton. “New York City [was] a cultural hub then as it is now. People were exposed to these long-necked dinosaurs labeled as Brontosaurus,” says Matthew Mossbrucker, a paleontologist at the Morrison Natural History Museum in Colorado. “Brontosaurus never really went away, especially in popular culture.”
A small number of paleontologists have been campaigning for the dinosaur’s restoration since the 1990s, says Mossbrucker. “I certainly agree with the analysis that Brontosaurus excelsus deserves to be recognized as its own genus.”
The paleontologists pored over 81 skeletons of diplodocids (a family that also features the well-known Diplodocus genus) and related dinosaurs, comparing more than 400 features in the animals’ bones. Instead of taking any species for granted, the team tallied up similarities between individual specimens.
“We can see which specimens group together and have particular characteristics that help identify them as a species,” says study coauthor Emanuel Tschopp, a paleontologist at the Universidade Nova de Lisboa in Monte de Caparica, Portugal. In most cases, the original designations about species held true, he said.
But the original Brontosaurus was distinct enough to deserve its own genus separate from Apatosaurus. Though many of the differences between the two dinosaurs were subtle, Apatosaurus had the wider, stronger neck of the two.
“Apatosaurus is in general more robust than Brontosaurus, even though both of them are very massively built,” says Tschopp.
The new analysis does not just restore Brontosaurus excelsus to its former name — it gives the dinosaur some companions.
“Some of the species that have been proposed for Apatosaurus came out closer to Brontosaurus than Apatosaurus in our analysis,” says Tschopp. “You have three species now in Brontosaurus that at some point in history were considered to belong to Apatosaurus.”
Brontosaurus is not the only dinosaur that may have been misclassified, the findings suggest. Tschopp and his team identified another, lesser-known diplodocid that they say deserves its own genus (which they named Galeamopus). Contrary to their findings with Brontosaurus, the paleontologists also decided that two diplodocids should share a genus (Supersaurus) after seeing so many similarities between the animals.
Whether the newly reidentified Brontosaurus is widely embraced is up to the paleontological community. “The move is now in the court of public opinion — if people use the names in the senses the authors propose, their perspective will have credibility. If their opinion is rejected, people will not use the names,” says Daphne Fautin, vice president of the International Commission on Zoological Nomenclature, which produces guidelines for assigning scientific names to animals.