Since it was first discovered in 1879, Brontosaurus has been a favorite of dinosaur lovers around the world.
The trouble is, it hasn't been officially recognized as a genus by paleontologists since 1903. However, a new study published in the open access journal PeerJ claims to have found evidence that supports Brontosaurus as its own entity once again.
Confused about why this is such a big deal? Here’s the backstory:
Fossils for Apatosaurus were first discovered in 1877. Like other sauropods, the specimen had a long neck, long tail, and a relatively small head. Two years later, a very similar dinosaur was discovered and was named Brontosaurus excelsus, meaning "thunder lizard." The identity of Brontosaurus was nearly immediately up for debate, because the specimen was missing its head and there weren't enough distinctions between the bones to say that Brontosaurus and Apatosaurus were actually different. Considering the two lived in the Western U.S. around the same time, it got confusing.
As Scientific American explains, it was decided that the two were actually the same genus in 1903. Because Apatosaurus was named two years before Brontosaurus, conventions dictated that it would be the name that stayed. The Brontosaurus moniker, then, would no longer be used, and the species discovered in 1879 was renamed Apatosaurus excelsus.
Something about Brontosaurus stuck in the minds and hearts of many, who refused to give up hope that the dinosaur existed independently of Apatosaurus.
Over the years, paleontologists have searched for clues that would exonerate Brontosaurus from being part of the Apatosaurus genus, but for all the evidence that suggested they were different, other studies presented data showing they were the same.
The new study claims to have used new technology to find a number of differences that they believe are enough to say for sure that Brontosaurus is its own genus. Additionally, many more sauropod species have been discovered since 1903, which significantly increased the body of knowledge about these dinosaurs.
"Our research would not have been possible at this level of detail 15 or more years ago," lead author Emanuel Tschopp from Universidade Nova de Lisboa explained in a press release. "In fact, until very recently, the claim that Brontosaurus was the same as Apatosaurus was completely reasonable, based on the knowledge we had."
The researchers believe they have found enough differences between Brontosaurus and Apatosaurus to consider them distinct from one another, including Brontosaurus having a slimmer neck than its relative, as dino expert Brian Switek explained in Smithsonian.
With living animals, it's possible to use DNA to figure out relationships between species, but it gets a little trickier when examining fossils When it comes to naming new species, there aren't exactly set rules about what or how many differences there need to be from to another. This can be tricky, and is often up for considerable debate.
On the surface, it might seem like the scientists are being indecisive and don't have a firm handle on things. In reality, they are merely taking their cue from what can be gleaned from the evidence, which is the essence of what science is about. Whether or not Brontosaurus will remain its own species will depend on further debate and further research.
"It's the classic example of how science works," co-author Octávio Mateus added in the release. "Especially when hypotheses are based on fragmentary fossils, it is possible for new finds to overthrow years of research."