Scientists: Triceratops and Torosaurus Are the Same Dinosaur

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:

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

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I think Jack Horner and John Scannella is going a little bit too far on this. Firstly, post-cranial material (fossil material that does not belong to the skull) of Torosaurus indicates that Torosaurus is 7.6 meters long, smaller than the 9 meter long Triceratops (I wonder whether John Scannella and Jack Horner even knows how small Torosaurus actually is compared to Triceratops). One of the only animals (if not the only) which shrink as they grow up is the paradoxical frog, and dinosaur species (eg. Allosaurus, Triceratops’s relatives Protoceratops and Centrosaurus) which fossils of nearly all ages found indicates that NO dinosaur grows up like that! Not only that, Horner and Scanella’s theory suggest that the solid frill in Triceratops grew the 2 holes on it’s frill as Triceratops mature. If that’s the case, why would they grow a solid frill in the 1st place if they would grow 2 holes on it’s frill in later life? I also think that Mark Goodwin and Jack Horner's theories on the Pachycephalosaurs are just as absurd. For Stygimoloch, it is highly unlikely that it grew spikes behind it's dome if they were to shrink in later life as that would be a waste. As for Dracorex, this webpage proves that like Stygimoloch, Dracorex IS NOT a Pachycephalosaurus: http://www.thedracorex.com/dracorex-faq.html
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Does any one have any idea of the number of fossils on which this reasigment is being made and how complete the trasition is from juvenile to adult. We wouldn't want any "missing links". I can't believe I just wrote that.
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More detail here:

http://www.newscientist.com/article/mg20727713.500-morphosaurs-how-shapeshifting-dinosaurs-deceived-us.html

Check the additional illustration. (linked)
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Triceratops skulls have always shown a great variety. It's been a challenge for paleontologists to figure out what's a deformed individual and what's a juvenile animal and what's a female or male individual. The process of identification has been complicated by the tendency among early researchers to name new species whenever a new fossil differed slightly from another.

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.
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The way I see it, the scientist can just say that the torosaurus is the evolved form of triceratops. now all we need is a cute basic form. protoceratops perhaps?
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