Brontosaurus makes thundering comeback in revised dino family tree

More than a century after Brontosaurus was crossed off the official list of dinosaurs, a team of paleontologists has restored the iconic name to the evolutionary family tree.

Although well known as one of the most iconic dinosaurs, Brontosaurus (the thunder lizard) has long been considered misclassified. Since 1903, the scientific community has believed that the genus Brontosaurus was in fact the Apatosaurus.

Now, an exhaustive new study by palaeontologists from Portugal and the UK provides conclusive evidence that the iconic long-necked dinosaur is distinct from Apatosaurus and as such can now be reinstated as its own unique genus.

Brontosaurus was never really gone as it was simply treated as a species of the genus Apatosaurus: Apatosaurus excelsus. So, while scientists thought the genus Brontosaurus was the same as Apatosaurus, they always agreed that the species excelsus was different from other Apatosaurus species.

Now, palaeontologists Emanuel Tschopp, Octavio Mateus, and Roger Benson say that Brontosaurus was a unique genus all along. But let's start from the beginning.

The research would not have been possible at this level of detail 15 or more years ago, explained Tschopp of Universidade Nova de Lisboa in Portugal, adding that until very recently, the claim that Brontosaurus was the same as Apatosaurus was completely reasonable, based on the knowledge they had.

The researchers applied statistical approaches to calculate the differences between other species and genera of diplodocid dinosaurs, and were surprised by the result. The differences they 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, explained Benson from the University of Oxford.

The study appears in the peer reviewed open access journal PeerJ.