Cochise College           Student Papers in Geology

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Roger Weller, geology instructor            regional geology  planetary  gems

Sarah Moore

Historical Geology
Spring 2008



            Triceratops was the largest ceratopsian and one of the most popular. They existed during the late Cretaceous Period. These were stocky, grand beasts with three powerful horns; a short one above the beak and two long, double-curved brow horns up to three feet in length.  They provided a fantastic weapon against predators and may have been used in mating rivalry and rituals.  When alive the triceratops’ horns were composed mainly of solid bone with a covering made of keratin, the same material that makes up your fingernails, which may have doubled the horns length. Sinuses found at the bases of each horn may have functioned as shock absorbers. These huge creatures stood 9.5 to 10 feet tall, were 25 to 30 feet long, and weighed in at about 15,000 to 25,000 pounds.

 Photo Copyright R. Weller/Cochise College and the Natural History Museum.

            The head of a triceratops was almost one-third of its body length and was the largest head possessed by a land animal. Their head possessed great flexibility in movement and weighed up to 400 pounds. Their large eye sockets suggest that sight was an essential sense to this animal’s livelihood. Their eyes were directed to the sides to widen their field of view, much like the modern day horse. The back of these massive creature’s skulls consisted of a shield or frill. The outer edge was lined with triangular bones that gave the frill a saw-tooth appearance. Thanks to a recent finding of an adolescent triceratops skull showed the horns and frill were fully developed. This shows the possible importance for visual communication and species recognition. Although the frill may seem to have been a formable defense mechanism, really it was less than an inch thick. It could have still served a purpose of looking threatening, such as a peacock spreading it feathers to appear larger and tougher. Some say the frill may have been brightly colored, which leads to the newest theories that claim the frill was used in courtship and dominance displays. Under the frill were many blood vessels that may have worked as a cooling system, such as elephant ears. The frill also attached to the mouth to increase the jaw muscles power.

Photo Copyright R. Weller/Cochise College

            Triceratops had a toothless, tough beak containing many cheek teeth. The lower and upper teeth would rub together making them self-sharpening. Also, when the teeth wore down they were automatically replaced with new ones, much like modern day shark’s teeth-replacement system. They were considered herbivores for many reasons other than their teeth set up. Triceratops’ gut was large enough to give the protozoa enough time to process the cellulose consumed; in other words like elephants their bodies can digest a tree branch but a human cannot.  Also, they had a cheek to chew into; the food was pushed back into the teeth to be chewed before swallowing. They most likely munched on cycads and other low-laying plants. Cycads were said to be poisonous meaning the triceratops would have had the ability to process the poisons or evolved that ability.

Photo Copyright R. Weller/Cochise College

                These colossal beings walked on all four, stubby but sturdy legs with hoof-like feet, that most likely resembled those of a modern elephant. Their robust hind limbs with four functional toes were larger than its forelimbs that had five toes each. Ralph Chapman and Kent Stevens discovered that triceratops’ elbows could lock in place, which shows they probably, slept standing up. Using their morphology (characteristics such as leg length and estimated body mass) and fossilized track ways triceratops are said to have great power but not great speed. They were completely covered in a thick, rough hide that would have been difficult to puncture.

            Triceratops most likely lived in vast herds; this is supported by the findings of bone beds. Also, horn usage is more prevalent in herding animals, such as deer and gazelle. When threatened these massive creatures probably charged its enemy like a modern rhino does; having the group support behind this defense most likely made it quite effective. Not much is known about the mothering habits of the triceratops other than they hatched from eggs. Recent studies show it was likely for many types of dinosaurs to raise their young in the herd, this is supported by a Canadian bone bed discovered that contained both adult and adolescent bones.

            These beasts existed during the late Cretaceous Period around 67 to 65 million years ago. They were among the last of the species to evolve before the Cretaceous-Tertiary extinction. Many triceratops fossils have been found, most often in the western parts of the United States and Canada. When the first triceratops fossil that was discovered near Denver Colorado was mistakenly identified as an extinct buffalo species Triceratops have become one of the most famous species and most studied.

Photo Copyright R. Weller/Cochise College and the Natural History Museum.



Works Cited

               Bjork, Phil, Tallman Erika. "TRICERATOPS (Triceratops horridus) State Fossil of South Dakota." 20 March 2008
Moravec, Josef. "TRICERATOPS prorsus." 19 March 2008
Immega, Neal. "Triceratops." 19 March 2008
Jacob, Ashley. "Triceratops Jurica Nature Museum ." 20 March 2008
Sanders, Robert. "Smallest Triceratops skull described ." 03.06.2006 19 March 2008
"Triceratops Dinosaur ." 19 March 2008
"Triceratops horridus "Horrible Three-horned Face"." 19 March 2008