Brontosaurus is back! New analysis suggests genus might be resurrected
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
Hannah Devlin, science correspondent
Tuesday 7 April 2015 12.52 BST
The Brontosaurus is famous for having been resigned to extinction twice – the second time when scientists concluded that it was another long-necked dinosaur that had been misclassified.
Now, the “thunder lizard” looks set to make a comeback, after a new analysis suggests that Brontosaurus skeletons really are distinct enough to warrant their own genus.
The scientists behind the work hope the findings will trigger the resurrection of the Brontosaurus genus, which was discarded by most academics more than 100 years ago.
“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 discovery of Brontosaurus dates back to the so-called “Bone Wars”, a period in the US when a wealth of new dinosaur fossils were being discovered and rival palaeontologists were racing to name as many as possible. Brontosaurus was hastily named in 1870, a few years after another bulky long-necked specimen, the Apatosaurus (deceptive lizard), was discovered.
By 1903, it had been relegated to a subset of the Apatosaurus family, but the dinosaur has lived on as a mainstay in popular culture. “It’s probably because when it was found it was one of the first really complete long-necked dinosaurs,” said Tschopp. “It also just has a really good name.”
The argument for bringing back the iconic title is entirely objective, the scientists say. “Although I was excited when I found it might be the case,” he added.
Professor Paul Barrett, a senior dinosaur researcher at the Natural History Museum in London, said he is ready to re-adopt the Brontosaurus title, based on the findings. “It’s the biggest study on this family, they martial 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’.”
Brian Switek, author of My Beloved Brontosaurus and amateur palaeontologist based in Utah, said: “I want to believe, but I’m not sure the Brontosaurus is here to stay just yet.”
The problem, he said, is that there is no standard way of picking which anatomical traits are significant, meaning there will always be a degree of subjectivity in drawing up distinctions between closely related species. Done a different way, another analysis could easily sink Brontosaurus back into the Apatosaurus genus. The question is unlikely to be definitively agreed, Switek predicts, without the discovery of new fossils, in particular a Brontosaurus skull.
The latest analysis focussed on the Diplodocidae clade, the family containing Diplodocus, Apatosaurus and several other long-necked specimens.
The Diplodocidae dinosaurs lived from 170 to 130 million years ago, and are distinguished by their short legs (they are sometimes dubbed the “dachshund” 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 around 50 skeletons and measured around 500 anatomical traits to assess the hierarchy of differences within the family. Statistically, they found there were two main groups: one containing more slender species, such as Diplodocus, and a second containing the bulkier Apatosaurus. Within the Apatosaurus group, though, there were further considerable distinctions, including the fact that Apatosaurus had a thicker neck, 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.
The distinction between species and genera is without clear rules, but should at least be self-consistent, the authors argue.
Unlike with 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.