Last November, palaeontologists announced the discovery of Dakotaraptor, a super-sized relative of Velociraptor that stalked the Hell Creek Formation of North America alongside Tyrannosaurus rex. It was a formidable animal, 18 feet in length, with 9.5-inch sickle-shaped claws on its feet.
The dramatic beast was described by Robert DePalma from the Palm Beach Museum of Natural History, based on a incomplete skeleton that included parts of the backbone, arms, legs, and feet. But now, Victoria Arbour from the North Carolina Museum of Natural Sciences has shown that one of Dakotaraptor’s bones—the wishbone, or furcula—isn’t what it seemed. It wasn’t even part of a dinosaur at all.
It was actually a piece of turtle shell.
Arbour and her colleagues noticed that the Dakotaraptor “wishbones” had features that aren’t seen in those of other meat-eating dinosaurs. Instead, they looked like they belonged to pancake turtles, which were common in the area where Dakotaraptor was found. The misidentified bones were probably the turtles’ entoplastra—part of the bottom halves of their shells, and the equivalent of collar-bones. It really is turtles all the way down.
“We stand corrected,” says David Burnham from the University of Kansas, who was involved in describing Dakotaraptor. It was an honest mistake: the dinosaur’s bones were surrounded by turtle remains, and one of the entoplastra was found under its arm.
“This is by no means an uncommon occurrence,” adds DePalma. Lucy, the iconic Australopithecus fossil discovered in 1974, had a misidentified baboon vertebrae in her spine for over 40 years before anyone spotted the error. And Utahraptor, an even bigger cousin of Dakotaraptor, was originally described together with the bone of a plant-eating dinosaur. “It happens more regularly than one might think, and we correct as needed—that’s how science works,” adds DePalma.
Indeed so. One wrong bone does not discredit the discovery of a truly impressive animal. Given the difficult nature of palaeontology, and the less-than-ideal condition of many fossils, it’s amazing that these errors don’t happen more often. And it’s always refreshing when scientists issue a swift mea culpa and correct things efficiently, as DePalma and Burnham have done, rather than spiralling into festering arguments.