The Case of the Brontosaurus

FAS Astronomers Blog, Volume 31, Number 14b.

When I was growing up, Brontosaurus was almost as famous as T. rex. However, Othniel Marsh made a mistake (maybe). In 1877, he discovered a dinosaur, which he named Apatosaurus ajax (Marsh 1877). Two years later, in 1879, he discovered another similar dinosaur, which he named Brontosaurus excelsus (Marsh 1879). In 1903, Elmer Riggs took a close look at the fossils of these two animals and determined they were, in fact, very similar (Riggs 1903). However, over time people became familiar with the name Brontosaurus and very few people knew of Riggs’ work. Therefore, Brontosaurus continued to appear in popular books and articles, while Apatosaurus remained mostly unknown. Eventually, because Apatosaurus was discovered and named first, Brontosaurus excelsus was officially renamed to Apatosaurus excelsus.

Brontosaurus didn’t completely disappear from the public’s imagination. The U. S. Post Office issued a series of stamps in 1989 and included Brontosaurus. Stephen Jay Gould wrote an essay entitled “Bully for Brontosaurus” (Gould 1991) in which he noted that the International Commission on Zoological Nomenclature changed their rules in 1999 to allow names that have become well known to supersede a primary or original name. This was, however, too late to officially save Brontosaurus (see Paleontology & Biostratigraphy).

In 2015, Brontosaurus received some help from a trio of scientists (Tschopp, et al. 2015) who argued that Marsh might have gotten it right after all and Brontosaurus is distinct from Apatosaurus. So, is it back? Well, I really can’t tell. There were many articles celebrating the return of Brontosaurus after the Tschopp paper came out in April 2015. And I can still find Brontosaurus toys out there. But I haven’t found a definitive statement that Brontosaurus is officially back.