New research from a duo at the Museum of the Rockies argues that the triceratops may never have been a distinct species, but rather the younger form of another dinosaur.
After comparing the skull shape of the triceratops to that of its close relative, the torosaurus, researchers John Scannella and Jack Horner concluded that the triceratops may actually be a juvenile form of the torosaurus (not an entirely different species), as dinosaurs' skulls could change shapes during their lifetime.
New Scientist explains:
Now Scannella and Horner say that triceratops is merely the juvenile form of torosaurus. As the animal aged, its horns changed shape and orientation and its frill became longer, thinner and less jagged. Finally it became fenestrated, producing the classic torosaurus form.
This extreme shape-shifting was possible because the bone tissue in the frill and horns stayed immature, spongy and riddled with blood vessels, never fully hardening into solid bone as happens in most animals during early adulthood. The only modern animal known to do anything similar is the cassowary, descended from the dinosaurs, which develops a large spongy crest when its skull is about 80 per cent fully grown.
Scannella and Horner's findings would help explain why only adult torosaurus fossils have ever been uncovered. According to New Scientist, "torosaurus will now be abolished as a species and specimens reassigned to triceratops."
As Boing Boing points out, the new research highlights one of the major challenges of paleontology: "Paleontologists are tasked with reconstructing the lives of animals nobody has ever seen alive. And that creates a world where the obvious just isn't."