Centrosaurus vs Monoclonius

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Centrosaurus Duel

Centrosaurus probably used its large nose horn for defense and to duel with other males for the right to mate.  .  . much like modern elk and deer do.  Centrosaurus was a medium sized Ceratopsian dinosaur of the mid-late Cretaceous Period.  (75 million years ago)   Monoclonius lived at the same time.  It was determined by a team that included Dr. Scott Sampson (of Dinosaur Train fame) that Monoclonius is a mistake.  He called it a "nomen dubian" or doubtful name.  Dr. Sampson thinks that what was once called Monoclonius is merely juvenile Centrosaurs.  

Monoclonius

Not all paleontologists agree with this but most probably do.  in 1990 Dr. Peter Dodson of the University of Pennsylvania  determined that there was enough evidence for Monoclonius to be a valid Genus.

Monoclonius was one of the dinosaurs discovered and named by Edward D. Cope in 1876.  Some Pygmy tribes in Central Africa tell stories of a large animal in the jungle called Emela-ntouka that sounds like a Monoclonius or a Centrosaurus.  No proof has ever been found of this, but it is a cool thought.

Size of the two Genus are somewhere between 2,200 and 6,600 lbs.  (1,000  and 2,994kg.).  I used to think that the name "Monoclonius" meant "single horn"... but it does not.  It means "singe sprout" and it has to do with the teeth of Monoclonius.   "Centrosaurus" means "Pointed Lizard."  (it must refer to the pointed horn)   I have seen skulls and drawings with the nose horn pointed with a curve towards the front and others with it curved towards the back. 

It does seem very likely that at least some if not all Monoclonius fossils are merely juvenile Centrosaurus.   Because of this I drew the Monoclonius with similar patterns of markings as my drawing of Centrosaurus....after all, Monoclonius probably was just a young Centrosaurus.  It may even be that the horn curved towards the back when the animal was immature and curved towards the front when a full sized adult.  Dr. John Horner thinks a similar thing seems to have happened with Triceratops horns.  The brow horns pointed kind of up in immature animals and full grown Triceratops had horns that curved forward presumably for better defense against T. rex and other Triceratops.    It also appears that on Centrosaurs  the hook-like ornamentation horns at the top of the frill are only seen in full sized adults.

Triceratops Adult with Forward Facing Horns

Triceratops Teen

Notice the way the horns point up not forward.