Why did scientists reject this name?

The skeleton of a long-necked and long-tailed dinosaur was found in Wyoming in 1879 by paleontologist Othniel Charles Marsh. Later, scientists named this giant herbivore, which lived in the Jurassic period about 150 million years ago, brontosaurus (Brontosaurus excelsus). However, in 1903, paleontologist Elmer Riggs discovered that B. excelsus was very similar to another dinosaur called Apatosaurus ajax, which the same Marsh had discovered in Colorado in 1877. The differences between them turned out to be so insignificant that scientists decided that it would be better to classify them both in the same genus or species group. Since Apatosaurus was first named, scientific naming conventions have retained the name, forcing scientists to abandon the name Brontosaurus.

More than 100 years later, researchers proposed resurrecting Brontosaurus as a separate genus. A sauropod study published in 2015 in the journal PeerJ found that the original fossils of Apatosaurus and Brontosaurus may have been different enough to classify them as separate groups.

The nearly 300-page study examined 477 physical features of 81 sauropod specimens. The initial aim of the study was to analyze the relationships among the species that make up the sauropod family known as Diplodocidae, which includes diplodocus, apatosaurs, and now brontosaurs.

In general, scientists have found that: brontosaurus’ neck was higher, narrower and smaller than that of apatosaurussaid lead study author Emanuel Chopp, a vertebrate paleontologist now at the University of Hamburg in Germany. They proposed three species of Brontosaurus: B. excelsus, B. parvus, and B. yahnahpin.

They call Brontosaurus “resurrected.” That sounds good. “Reanimated” is certainly the correct term, but “resurrected” is the official description of what they do.
Jacques Gauthier, curator of reptiles at the Yale Peabody Museum of Natural History, says he was not involved in the research.

Emanuel Chopp stated that this decision was determined by time and new findings. Even 15 years ago, scientists didn’t understand what made these groups unique.

Almost a decade has passed since the paper was published, and Chopp says: “Not everyone readily accepts such proposals. Individual researchers, not fully confident in the results, continue to use the name Apatosaurus for what others have already called Brontosaurus.” Still, paleontologists say the 2015 study “provides strong arguments that most experts find quite convincing.”