Triceratops

## TriceratopsThree-horned Face

* Male
* Old Male
* Female
* Juvenile

* **Skull Length** of 2.5 - 2.62 meters (8 feet, 3 inches - 8 feet, 7 inches)
* **Horn (bone core) Length** of 1.15 meters (3 feet, 9 inches)
* **Frill Width** of 2 meters (6 feet, 7 inches)
* **Life Expectancy** of at least 60 years
* Skull is composed of fibrolamellar bone, which contains fibroblasts that help heal bone injuries quickly

 **Main** Segments Gallery

MainSegmentsGallery

***“ Many different species of dinosaur live in forests. Triceratops, one of the biggest in North America. They can be 26 feet long. The huge frills on their heads can be used for protection when they fight. ”***

― **David Attenborough**, *Forests*
***Triceratops*** (Three-horned Face) is a genus of chasmosaurine ceratopsid dinosaur that lived in western North America 68 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period. It is one of the most well-known dinosaurs to have ever walked the Earth. The species depicted on Prehistoric Planet is likely *Triceratops horridus*, with its shorter nose horn and shallower snout.

## Paleobiology

### Size, Physique, and Head Ornamentation

***“ This young male looks to be in prime condition, showing off his meter-long horns and his colorful head frill. His horns appear perfect, not yet damaged by battle. To a female, however, the absence of any wear and tear might suggest a potentially-critical weakness; a lack of experience. ”***

― **David Attenborough**, *North America*
*Triceratops* is one of the last ceratopsians, known to most as the horned and frilled dinosaurs. The iconic brow horns of *Triceratops*, each at least a meter (3 feet, 4 inches) long, along with their wide frills of solid bone (as opposed to the frills of other ceratopsids, which tend to have holes to lighten their weight) that could be as long as a third of the animal's whole length, make them one of the most recognizable dinosaurs ever known. One specimen, known as "Yoshi's Trike" (MOR 3027), has horns 1.15 meters (3 feet, 9 inches) long. Accounting for keratin sheaths and the fact that Yoshi's Trike is not yet fully mature when it died, fully-grown *Triceratops* possibly had horns that grew longer than 1.2 meters (4 feet). On Prehistoric Planet, Yoshi's Trike likely served as the basis of the 30 year-old, 10-tonne veteran male seen in North America. Another *Triceratops horridus* specimen, known as "Big John", may be another possible inspiration, standing three meters (10 feet) tall, eight meters (26 feet) long, with a skull that is 2.62 meters (8 feet, 7 inches) long and 2 meters (6 feet, 7 inches) wide. Big John is believed to have been 60 years old when it died. Though the specimen bore a gaping scar on its collar (likely caused by a rival *Triceratops*, further supporting the use of horns in intraspecific combat), given how the traumatic lesion showed signs of healing, it is believed that this wound was not the cause of Big John's death.

### Jaws and Dentition

The front part of a *Triceratops* bill is toothless, while the rest of the mouth is packed with "dental batteries", tightly-packed teeth. Unlike hadrosaurids, which developed their dental batteries into grinding surfaces to grate plants into fine pieces, ceratopsians evolved their teeth to provide cutting surfaces for shearing through tough vegetation, with this difference in function indicating that they evolved their chewing capabilities independently. Ceratopsids are believed to have only fed on plants that were, at most, just one meter (3 feet) in height, while gut microflora broke down plants in their stomach via fermentation.

On Prehistoric Planet, ceratopsians like *Triceratops* and *Pachyrhinosaurus* are depicted with cheeks, in sharp contrast with the other type of marginocephalians, pachycephalosaurs like *Pachycephalosaurus* and *Prenocephale*, which are depicted without cheeks. Using the works of Dr. Ali Nabavizadeh as justification, Dr. Darren Naish, lead consultant of Prehistoric Planet, brought up how pachycephalosaurs had simpler, more primitive teeth, and hence chewed food more like a lizard rather than doing so in the more complex manner in which ceratopsians and ornithopods chewed. Regardless of how this debate eventually gets resolved, current understanding has it that dinosaur cheeks aren't like those of mammals, since, contrary to popular belief, dinosaurs did not need cheeks to hold food, and one theory is that they may have had "cheeks" as a result of jaw muscles extending across the parts where true cheeks would be.

### Prehistoric Planet's Depiction

*Main: *Triceratops* on Prehistoric Planet*

Main: *Triceratops* on Prehistoric Planet

Prehistoric Planet depicts *Triceratops* as mottled green with beige countershading. Also, based on evidence, the ceratopsians of the series are shown with large, polygonal scales and feature scales, along with a forelimb gait unlike that of large, quadrupedal mammals. The adults show individual variation in terms of head ornamentation, with females having yellow stripes running down their frills and thin horns that curve upwards and fork out, forming a wide, V-shaped gap between them, while males have blood-red frill stripes and thicker horns that tend to curve downwards then forwards, usually closer together, almost parallel to each other. The lengths of the horns also vary, likely due to age, some sport asymmetrical horn lengths or bear some battle damages, like horn tips chipped or even snapped off. The 30 year-old male from North America even bears a large notch on the right edge of his frill, possibly a bite mark from a *Tyrannosaurus*. Juveniles, stated in Forests to weigh a fiftieth of their parents, also have their appearance based on discovered differences between them and the adults, like shortened faces and horns turned upward in an almost-vertical orientation.

The skull of a *Triceratops*, with the skulls of a *Quetzalcoatlus*, *Mosasaurus, Barbaridactylus*, and a smaller *Triceratops* skull in the background, appears in the opening of every episode of Prehistoric Planet's second season. *Triceratops* first appears in the second segment of Freshwater, where a *T. rex* feeds on a large *Triceratops* it took down just recently. *Triceratops* next appears in the second segment of Forests, which shows a small herd of them traveling to a cave in order to consume the mineral clay needed to neutralize the toxins of the plants they ate. The ceratopsians make a brief appearance in the fifth and final segment of Swamps, where several of them gather to feed on the lush vegetation, all the while keeping an eye out on two *T. rexes* in the area, looking for their next prey. The species makes one last appearance in the fourth segment of North America, where several of them gather in the forests near the Rocky Mountains for the mating season. *Triceratops* was also the focus of an Uncovered segment, "Why Did *Triceratops* Have A Frill?", which discusses the purpose of their frills for display and defense.

## Paleoecology

### Paleoenvironment

*Main: Hell Creek Formation*

Main: Hell Creek Formation

***“ Further north, the Rocky Mountains are still slowly rising. And as they do, they create higher, cooler landscapes where vast pine forests flourish. ”***

― **David Attenborough**, *North America*
*Triceratops* lived 68 - 66 million years ago in Laramidia, an island continent that would one day become western North America, which, by that time, was split in half by an inland sea. Given the formations it appeared in, *Triceratops* appears to prefer subtropical inland forests, swamps, and rivers (as seen in the Hell Creek Formation, which, though warmer than Montana and South Dakota today, was kept humid by sufficient levels of rainfall).

***“ At last, the herd reaches the place they need to visit. This is the antidote; a special clay. These are known as clay licks, and they're visited time and again. ”***

― **David Attenborough**, *Forests*
It is justifiably plausible that, much like some animals today, *Triceratops* may have engaged in geophagy to protect their stomachs from the toxins of the plants they ate. In the newly-forming Rocky Mountains, it is believed that there were limestone caves during the time of *Triceratops*, providing possible clay lick sites for the dinosaurs.

### Paleofauna

***“ Here, in spring, new plant growth creates new feeding grounds for the gathering herds. But where there are large numbers of plant-eaters, there are great hunters... ”***

― **David Attenborough**, *Swamps*
*Triceratops* would have coexisted with animals like *Edmontosaurus*, *Ankylosaurus* and *Pachycephalosaurus*, as well as some dromaeosaurs like *Acheroraptor* and troodontids like *Pectinodon*. Given their large size, adult *Triceratops* would have only needed to be wary of one hunter, the apex predator of the regions it lived in, *Tyrannosaurus rex*. *Triceratops* would have also coexisted with *Torosaurus*, a similarly-sized ceratopsian with one of the largest heads of any land animal (around 2.8 meters, or 9 feet, 2 inches), made light by holes in the frill (as opposed to *Triceratops*, which has a shorter frill of solid bone). At one point, *Torosaurus* was considered a more mature form of *Triceratops*, though this theory is not that supported today, especially given the presence of very old *Triceratops* specimens like Big John as well as apparently subadult *Torosaurus* specimens. Another ceratopsian, the dog-sized *Leptoceratops* (around 2 meters, or 6 feet and 7 inches, in length), also coexisted with *Triceratops*.

In a 2011 study that estimated the proportions of large-bodied dinosaurs in the Hell Creek Formation, it was revealed that *Triceratops* made up 40% of all dinosaurs in the region, making it the most common dinosaur in Hell Creek, with *T. rex* (making up 24% of Hell Creek's dinosaur population) being the second most abundant.

As one of the last non-avian dinosaurs, *Triceratops*, along with most of the animals it coexisted with, would have bore witness to the K-Pg Extinction Event 66.043 million years ago, a catastrophe that would ultimately wipe out three-quarters of all life on Earth, including all non-avian dinosaurs.

### Feeding Preferences and Adaptations

In terms of feeding, the type of plants *Triceratops* ate is still not entirely clear, with suggestions ranging from palms and cycads to ferns. It is presumed that, with its deep, narrow beak, *Triceratops* plucked low vegetation (though the animal could potentially ram and knock down taller plants and trees), and sheared through these large volumes of fibrous plants with its dental batteries. Prehistoric Planet depicts *Triceratops* as practicing what some elephants do today, heading for caves to ingest minerals. Animals engage in geophagy (the consumption of soil) either to counteract and neutralize the toxins of the plants they ate, or to supplement their diet with extra nutrients (animals that tend to do this usually live in areas or conditions where nutrition is poor and essential minerals are hard to come by). Prehistoric Planet went with the former reason, though the latter is still considered a possibility.

### Social and Mating Habits

***“ The mating season has arrived for one of North America's most heavily-armed dinosaurs. Triceratops. Every year, large numbers of these giants gather in clearings. The females have come to choose a mate. Six-tonne males fight and display their strength. ”***

― **David Attenborough**, *North America*
In terms of social behavior, unlike most ceratopsids (mostly centrosaurines, which have been found in mass bone beds), *Triceratops* doesn't appear to travel in large herds numbering in the dozens. Remains of several *Triceratops* indicate that they traveled in small groups of 5 - 10 individuals, which can be observed in Forests and Swamps. The only time more appear to come together is during the mating season, as seen in North America, where large numbers of them gather in clearings, with the females looking for suitable partners, and males fight and show off their strength to cement their mating priorities.

### Agonistic Behavior

In terms of fending off threats, the large horns, frill, and overall size and mass of *Triceratops* are enough to serve as a warning of the brute force and danger that the animal is capable of bringing forth. Even so, this is not a guarantee of their safety, as seen in the second segment of Freshwater, where one was just recently slain by an old male *Tyrannosaurus*, which, as indicated by his many scars and wounds (including the new ones the *Triceratops* inflicted on his right leg in the struggle), has gone through decades of fighting and bringing down large, dangerous prey, and still lived to fight another day. This segment depicts the old *T. rex* feeding on the *Triceratops* starting from the neck. As a study in 2012 suggests, *T. rex* likely focused on the nutrient-rich neck muscles behind the frill of a *Triceratops* (which, in life, were necessary to help the ceratopsian support the great weight of its head). Conversely, the 30 year-old veteran male *Triceratops* in the fourth segment of North America appears to have what is likely a *T. rex* bite mark on the right edge of his frill, an indication that, much like the old *T. rex* from the second segment of Freshwater, he, too, has fought and possibly even brought down dangerous predators, his continued survival serving as proof of his experience and dominance in life.

***“ A 30 year-old male, weighing more than 10 tonnes. If there's one thing that he has in spades, it's decades of wear and tear. He may be old, but he's still strong enough to challenge a young rival, however fit. The stakes are high, and neither is willing to back down. ”***

― **David Attenborough**, *North America*
*Triceratops* could also clearly use their horns for fighting others of their own kind. To settle disputes, the males would lock horns, using their weight and experience to overpower the enemy and emerge victorious. This can result in all sorts of injuries, from snapped horns to even punctured frills, as was the case for the Big John specimen. Even so, as tough animals, *Triceratops* are expected to heal and recover from such injuries, as Big John, believed to be 60 years old at the time of its death, apparently did not die as a result of its large traumatic lesion.

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A 30 year-old male (right) challenges a younger male (left)The veteran lifts his rival up by the face to throw him to the groundThe veteran has attracted a female
## Trivia

* *Triceratops* is the second animal on Prehistoric Planet that was first introduced deceased (having been slain by a *T. rex* before the events of the second segment of Freshwater). The first was *Nemegtosaurus*, shown as a moderately-sized carcass (significantly smaller than a Mongolian Titan) surrounded by four *Tarbosaurus* in the second segment of Deserts.

## References

### General

1. ↑ 1.0 1.1 1.2 Big John, largest known *Triceratops* skeleton, sold at auction
2. ↑ 2.0 2.1 2.2 Big John, largest known *Triceratops* skeleton, goes on display before auction
3. ↑ 3.0 3.1 Flavio Bacchia, supervisor of Big John's assembly, determined that it was 60 years old when it died
4. ↑ 4.0 4.1 Histological and chemical diagnosis of a combat lesion in Triceratops
5. ↑ A functional analysis of jaw mechanics in the dinosaur *Triceratops*
6. ↑ Feeding height stratification among the herbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada
7. ↑ "Resource Exploitation and Habitat", Sampson (2001); page 268.
8. ↑ Dinosaur Census Reveals Abundant *Tyrannosaurus* and Rare Ontogenetic Stages in the Upper Cretaceous Hell Creek Formation (Maastrichtian), Montana, USA
9. ↑ Dinosaur extinction battle flares
10. ↑ Elgon elephants on Mount Elgon Foundation
11. ↑ The Elusive Elgon Elephants
12. ↑ More than old bones: New study sheds light on *Triceratops* behavior and living habits
13. ↑ How to eat a *Triceratops*: large sample of toothmarks provides new insight into the feeding behavior of *Tyrannosaurus*

### Dr. Ali Nabavizadeh

1. ↑ New Reconstruction of Cranial Musculature in Ornithischian Dinosaurs: Implications for Feeding Mechanisms and Buccal Anatomy
2. ↑ Dinosaurs did not need cheeks to hold their food since they don't chew from side to side the way mammals do.

### Dr. Darren Naish

1. ↑ Pachycephalosaurs likely lacked cheeks because of their primitive teeth.
2. ↑ After basing off of Dr. Ali Nabavizadeh's works regarding pachycephalosaur chewing styles, the decision was made to depict pachycephalosaur anatomy as being more fit for lizard-style chewing as opposed to the more complex chewing styles of ceratopsians and ornithopods, further showcasing the anatomical diversity of ornithischians.
3. ↑ The look of *Triceratops* is based on new information on skin and scale anatomy, as well as forelimb gait (which wasn’t like that of big quadrupedal mammals).
4. ↑ Juvenile *Triceratops* looked different from the adults based on actual evidence. These differences include shortened faces and almost vertical brow horns.
5. ↑ 5.0 5.1 *Triceratops* may have visited caves much like the elephants, rhinoceros, and bushbucks of Mt. Elgon in Kenya, Africa visit underground caves to mine salt-rich clay, and the Rocky Mountains, which were just rising around that time, likely had many limestone caves that can potentially provide these clay licks. Such behavior is widespread in the natural world today, mining rock faces for mineral content, either to neutralize the toxins of the plants they digested, as depicted on Prehistoric Planet, or to supplement their diet with various minerals.

### Dr. Thomas Holtz

1. ↑ GEOL 104 Dinosaurs: A Natural History - Marginocephalia: That's Using Your Head!
2. ↑ Lecture 17 Thyreophora Defense! Defense! DEFENSE!!

### Prehistoric Planet

1. ↑ As stated in Forests.
2. ↑ As stated in North America.