Despite its relegation to a subset of the Apatosaurus family in 1903, new research suggests that the Brontosaurus is distinct enough to be a genus

The Brontosaurus has been consigned to extinction not once, but twice – the second time when scientists concluded it was too similar to other long-necked dinosaurs to deserve its own genus.

Now the “thunder lizard” looks set to make a comeback, after a new analysis suggests that Brontosaurus specimens are sufficiently distinct from other species after all.

The team behind the findings hope they will trigger the resurrection of the Brontosaurus moniker, more than 100 years after it was discarded by academics.

“It’s a nice example of how science works. A new finding can overturn more than 100 years of beliefs,” said Emanuel Tschopp, who led the study at the Nova University in Lisbon.

The first Brontosaurus specimen was unearthed during the so-called “Bone Wars”, when rival scientists were competing to name as many new specimens as possible. The palaeontologist Othniel Charles Marsh hastily declared Brontosaurus to be a new genus in 1879, two years after naming another bulky long-necked specimen, the Apatosaurus (deceptive lizard).

The discovery of a third intermediate species cast doubt on the claim, however, suggesting the whole lot would be more sensibly designated as a single group. By 1903, the Brontosaurus had been relegated to A. excelsus, a subset of the Apatosaurus family – but to the present day it has lived on as a mainstay in popular culture.

“It’s like a scientific zombie that has kept shambling on for one reason or another,” said Brian Switek, author of My Beloved Brontosaurus and amateur palaeontologist based in Utah. “Partly, it’s just a wonderful name. It sounds big.”

Facebook Twitter Pinterest Brontosaurus as researchers imagined it in the late 1800s. Photograph: Picasa

Facebook Twitter Pinterest Brontosaurus as researchers see it today, with a Diplodocus-like head. Photograph: Davide Bonadonna

The newly proposed revival is the unexpected outcome of a re-assessment of the hierarchy of the entire Diplodocidae clade, the family containing Diplodocus, Apatosaurus and several other long-necked specimens.

The group lived between 170 to 130 million years ago and are distinguished by their short legs (they are sometimes dubbed the “dachshunds” of dinosaurs) and incredible length. The average length of an Apatosaurus was 22m, but a related species, Supersaurus, was thought to have reached 34m head to tail.

The scientists analysed 81 skeletons and measured around 477 anatomical traits to create a new evolutionary family tree. Statistically, two main groups emerged: one containing more slender species, such as Diplodocus, and a second containing the bulkier Apatosaurus. Within the Apatosaurus group, though, further considerable distinctions were found. Apatosaurus had a thicker neck than the original Brontosaurus specimens, and differences were seen in the shape of their shoulder blades and ankle bones, according to the PeerJ report.

“The differences we found between Brontosaurus and Apatosaurus were at least as numerous as the ones between other closely related genera, and much more than what you normally find between species,” said Roger Benson, a co-author from the University of Oxford.

Professor Paul Barrett, a senior dinosaur researcher at the Natural History Museum in London, is among those ready to re-adopt the Brontosaurus title, based on the findings. “It’s the biggest study on this family, they marshal a lot of evidence and make a very good case,” he said.

“It’s taken us a long time to convince people that we shouldn’t be using the name ‘Brontosaurus’,” he added. “Just as we’ve got to that point, it looks like we’re going to have to turn around and say ‘Actually, it’s alright again’.”

Others are more hesitant. “I want to believe, but I’m not sure the Brontosaurus is here to stay just yet,” said Switek.

The problem, he says, is that there is no standard way of picking which anatomical traits are significant, meaning there is a degree of subjectivity in drawing lines between related genera. Using a different set of anatomical markers could easily sink Brontosaurus back into the Apatosaurus genus. The question is unlikely to be definitively agreed, Switek predicts, without the discovery of fresh fossils, in particular a Brontosaurus skull, which has never been found.

Unlike for living species, there is no official procedure for creating a new genus or reinstating an old one, and whether Brontosaurus makes a comeback will depend on popular consensus within the community. “Other researchers will now need to test the evidence for resuscitating Brontosaurus,” said Tschopp.

The authors said the research was only possible due to the recent discovery of several new dinosaurs similar to both Apatosaurus and Brontosaurus, which made it possible to undertake a detailed investigation of how different they actually were.

“Our research would not have been possible at this level of detail 15 or more years ago,” said Tschopp. “In fact, until very recently, the claim that Brontosaurus was the same as Apatosaurus was completely reasonable, based on the knowledge we had.”

Irrespective of the scientific outcome, the dinosaur is likely to live on in the popular imagination. “The ghost of Brontosaurus will always be with us,” said Switek.