The name of the Peabody Museum of Natural History’s dinosaur icon is up in the air.
Standing outdoors on a 13-foot-high granite platform, the 7,350-pound bronze, horned dinosaur welcomes visitors to the museum. Looking at the Torosaurus statue through the window of her office, Peabody Museum Deputy Director Jane Pickering said the area is a prime spot for tourist photos.
“The statue has become a symbol of the museum,” Pickering said.
Sculpted by artist Mike Anderson, the statue will celebrate its fifth birthday Friday. But as the Peabody Museum celebrates, the Peabody mascot is going through an identity crisis.
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As of now, a plaque introduces the statue as Torosaurus latus, but that name is now up for debate. Montana State University researchers John Scannella and Jack Horner argue that the Torosaurus is not a distinct dinosaur species — in fact, it is just an adult Triceratops, the researchers claimed in a paper published July in the Journal of Vertebrate Paleontology. But Yale paleontologists Nick Longrich and Jacques Gauthier said they have evidence that Yale’s torosauruses are not adults, so they cannot be adult triceratopses.
The seemingly trivial matter of a dinosaur’s name crystallizes a broader debate in paleontology. Since all paleontologists have are pieces of bones, identifying species poses a challenge that divides some scientists into “splitters,” who look at differences and create new species, and “lumpers,” who look at similarities and merge species. Lumping and splitting species affects how scientists understand the past, Horner said.
“Whether one species is another won’t cure cancer, but it gives us a new snapshot of what life was like 65 million years ago,” Horner said.
In 1891, famed fossil hunter John Hatcher 1884 sent Yale professor and Peabody curator Othniel Marsh two horned dinosaur skulls from Wyoming. Since both skulls had a frill punctured with two large holes, Marsh dubbed them Torosaurus, which can be translated as “pierced lizard.”
Marsh also named the Triceratops. The Triceratops looks like the Torosaurus except the edge of the Triceratops’ neck frills are sometimes bordered by bony triangular knobs. The Triceratops also has no frill holes.
Over a century later, Anderson chose the Torosaurus after members of the Peabody Museum asked him to sculpt a Marsh-named dinosaur statue for the museum’s front lawn. The Torosaurus won Anderson over with its massive eight-foot long skull, rhinoceros-like body and general bizarre appearance, he said.
To build the statue, Anderson turned to paleontologist Andrew Farke, an expert on horned, frilled dinosaurs for guidance. Since no complete Torosaurus skeletons have been found, Farke said, the Triceratops, believed to be the Torosaurus’ closest cousin, was used as a model. Everything under the head of horned dinosaurs are nearly identical, Farke said so only the skulls really matter.
In 2005, the bronze statue arrived at the Peabody Museum, greeting visitors with its horn studded face, open beak and Triceratops body.
“[The statue is] basically a Triceratops with a Torosaurus skull,” Anderson said.
After observing hundreds of Triceratops and Torosaurus specimens excavated from rocks called the Hell Creek formation in Montana, Horner said he was convinced the two are the same species. After conducting a study on how the Triceratops morphed with age in 2006, Horner said he had suspicions that the two key difference between the two dinosaurs come from different growth phases.
Although the Triceratops has distinctive bony knobs missing on the Torosaurus, the knobs change from looking like arrowheads to flattened pyramids as the triceratops aged. While the Torosaurus has frill holes that are missing in the Triceratops, as the Triceratops aged, Horner said the frill thins in the areas the Torosaurus has its frills, indicating hole formation.
To confirm his suspicions, Horner analyzed growth pattern on the interior surface of bones from the two dinosaur species. Since all bones change with time, researchers can use them to tell if an animal was in a period of fast or slow growth. From these observations, Horner and Scannella concluded the Triceratops is a teenage Torosaurus.
In July 2009, Horner and Scannella published their paper, lumping the Torosaurus and the Triceratops into one species, contrary to Marsh, who had split them.
“It’s easy to be a splitter,” Horner said. “A fourth grader can do that, even a first grader can do that.”
While researchers tend to like to name new species, they also need to re-evaluate current dinosaur species, Horner said.
But Yale researchers remain unconvinced.
After the July 2009 paper, Yale paleontologist Nick Longrich traveled to the West Campus to see the Torosaurus skulls Marsh described. If Horner’s assertions are true and all Torosaurus skulls are that of adults, then the skulls would not have any juvenile features, such as unfused bones. But it appears they do, Peabody Museum director Derek Briggs said.
To confirm his suspicions, Longrich said he plans to look into the bone growth patterns of Yale’s specimens. But before Longrich can do that, Briggs said the plaster and brown paint used to reconstruct the skulls decades ago must be removed.
While Longrich does not have the results yet, other paleontologists have also remained unconvinced.
Andrew Farke said Horner’s argument still has some questions to address before Farke can accept it. For one thing, the number of bony knobs along the edge of the frill rarely change as dinosaurs get older, but Triceratops specimens have fewer knobs than Torosaurus specimens. Farke also pointed out that frill holes tend to develop early in other frill-holed dinosaurs, making the Triceratops odd for its late hole development.
“I’m not entirely ready to jump on board yet in saying they’re the same thing,” Farke said. “Ask me in a year.”
STILL A YALIE
As for the statue’s nameplate, Pickering said it’s unlikely that name will change. So far, it’s just one group that’s arguing for the Torosaurus to be placed in the same species as the Triceratops, Pickering said, but more researchers need to confirm the idea.
“Our scientists don’t completely accept the assertions of the authors,” Pickering said. “It’s going to be a storm in a teacup.”
Pickering said she doesn’t mind the name change either way because both the Triceratops and the Torosaurus were named by a Yale professor, Othniel Marsh.
“Either way,” Pickering said, “it’s still a Yale dinosaur.”