John Scannella and Jack Horner, researchers at the Museum of the Rockies in Bozeman, Montana, say that the triceratops is the same dinosaur as another one called the torosaurus. The skeletal remains of the three-horned animal are actually the undeveloped, juvenile form of the torosaurus:
The torosaurus will now be abolished as a separate species and remains from it reclassified as triceratops.
Link via Super Punch | Photo by Flickr user etee used under Creative Commons license
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.
The torosaurus will now be abolished as a separate species and remains from it reclassified as triceratops.
Link via Super Punch | Photo by Flickr user etee used under Creative Commons license
http://www.newscientist.com/article/mg20727713.500-morphosaurs-how-shapeshifting-dinosaurs-deceived-us.html
Check the additional illustration. (linked)
And then you had Torosaurus, where the skull is largest of any animal that ever lived on land, but the body is the same as Triceratops--and no juveniles showing the identifying features have been found.
A lot of progress has been made on this is in the past two decades. It's fascinating what we're finding out about the plasticity of ceratopsian bone and the life stages of these creatures.
Congratulations, and thanks, to all researchers involved.