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amined bones in 18 different museums in the United States and Europe and studied photos and drawings from other specimens. The idea was to get a high-resolution family tree by examining many individual specimens, rather than focusing only on fossils that represent an entire species. The study included six specimens of Apatosaurus excelsus, as Brontosaurus has been called By Michael Balter How Brontosaurus lost its name in the since 1903. first place is the stuff of dino legend. DurTschopp and colleagues found that A. hat’s in a name? Sometimes plenty, ing the “Bone Wars” of the late 19th century, excelsus differed from the three other recas the U.S. Postal Service (USPS) paleontologists Edward Cope and Othniel ognized species of Apatosaurus in at least found out in 1989 when it issued Marsh marauded through the American a dozen key characters across the skeleton. colorful dinosaur stamps, includWest bitterly competing for dinosaur fossils, That’s as many differences as seen between ing one for Brontosaurus. Palewhich led to some rapid and slapdash degenera long accepted as distinct, such as ontologists and educators loudly scriptions. In 1877, Marsh published a brief Diplodocus and Barosaurus. For example, protested that the correct scientific name note on one of his skeletons, calling it Apatoa true Apatosaurus has a bulkier neck and for the iconic beast was Apatosaurus— saurus (“deceptive lizard”). Two years later, was “even more robust than Brontosaurus,” a fact that even lay dino aficionados and he published an equally brief report on a Tschopp says. But Brontosaurus also has many 8-year-olds took pride some features that Apatosauin knowing. The Smithsonrus lacks, such as a rounded ian Institution accused USPS expansion of one edge of its of favoring “cartoon nomenshoulder blade and a longer clature to scientific nomenbone in its ankle. clature.” It didn’t help that Given these anatomical difthe stamps were officially ferences, “It would be unfair to launched at Disney World. lump Apatosaurus and BronNow, a dinosaur-sized study tosaurus together,” Upchurch of the family tree of the Disays. Mannion agrees, and also plodocidae, the group that inendorses the team’s finding cludes such monstrous beasts that another Diplodocidae geas Apatosaurus, Diplodocus, nus, Eobrontosaurus, should and Barosaurus, finds that be included within BrontosauUSPS got it right: The fosrus, giving the genus a few adsils originally called Brontoditional species to call its own. saurus show enough skeletal Some paleontologists have differences from other specireservations. “It’s going to mens of Apatosaurus that force us to ask questions about they rightfully belong to a what we really mean by genus different genus. The study, and species in a paleontologipublished online this week The U.S. Postal Service caught flak for calling these giant plant-eating dinosaurs cal context,” says paleontoloin the journal PeerJ, brings Brontosaurus in 1989, but now scientists say the genus name is valid after all. gist John Whitlock of Mount the long-banished name back Aloysius College in Cresson, into scientific respectability as a genus cosupposed new genus, Brontosaurus (“thunPennsylvania. “Is it more useful to distinequal with Apatosaurus. der lizard”). By 1903, paleontologists had guish specimens as Brontosaurus and Apa“I didn’t start out trying to resurrect decided that the two beasts were too similar tosaurus than it is to distinguish A. excelsus Brontosaurus,” says lead author and paleto be divided into separate genera. Because from other species of Apatosaurus? I don’t ontologist Emanuel Tschopp. He was just Apatosaurus had been named first, it had know, but I hope it’s the start of a convertrying to better understand the evolutionprecedence under the rules of scientific nosation.” He and others, including Tschopp ary relationships among all Diplodocidae menclature. Paleontologists confirmed this himself, note that the characters used aren’t as part of his Ph.D. thesis at the New Uniconclusion in the 1970s, and know-it-all cut-and-dried and could be scored differversity of Lisbon. Indeed, paleontologists children have instructed their parents ever ently by others. are impressed by the scope of the new since that “Brontosaurus” isn’t a valid name. Upchurch thinks this kind of detailed taxstudy, which included 81 skeletons and (The taxon had its defenders, including evoonomy could help resolve questions such as 477 skeletal features or characters, far more lutionary biologist Stephen Jay Gould in his how diverse dinosaurs were just before they than any previous analysis. “Emanuel’s “Bully for Brontosaurus” essay.) went extinct about 66 million years ago. data set is now the largest published so In the new analysis, Tschopp looked at Others welcome the resurrection of an icon. far” for plant-eating dinosaurs, says Philip every Diplodocidae specimen he could get “Brontosaurus has a prominent place in the Mannion, a paleobiologist at Imperial Colhis hands on. These plant-eating dinos public imagination,” Mannion says. “It can lege London. The name change is likely to lived in today’s North America and Europe only be a good thing that it is back with us. stick, adds paleobiologist Paul Upchurch of between 160 million and 145 million years … It shows that science develops through University College London: “I will be happy ago; their long necks and tails stretched up time and that it’s possible to change our to start using Brontosaurus again.” to 35 meters from end to end. Tschopp exminds, even about long-held views.” ■ PALEONTOLOGY
Bully for Brontosaurus!
A comprehensive study of one branch of the dinosaur family tree resurrects Brontosaurus as a valid genus
10 APRIL 2015 • VOL 348 ISSUE 6231
Published by AAAS
IMAGE: LEFTERIS PAPAULAKIS/SHUTTERSTOCK.COM