Triceratops: The Three-Horned Tank

Triceratops is undoubtedly one of the most well known, and well loved, members of Dinosauria. It is second only to its main predator, Tyrannosaurus, and fits into the small niche of popular prehistoric animals (Stegosaurus, Brachiosaurus, Velociraptor, and Dimetrodon also fall into this elite group). Triceratops is known far and wide due to its great fossil distribution and the intensive study of its fossil remains. Triceratops is a main staple of museums, right alongside Tyrannosaurus. However, there are definitely some parts of Triceratops that are not as they seem, and will remain a mystery sealed by the marching of time.

The Holotype specimen of Triceratops was uncovered in Denver, Colorado in 1887 and consisted of two brow horns attached to a bit of the skull roof. This specimen got sent to Paleontologist, Othniel Charles Marsh (Famous for the Bone Wars), who, upon investigation, thought they belonged to a large bison from the Pliocene. Because of this, he named this first specimen Bison alticornis. After seeing the remains of other horned dinosaurs, (known as Ceratopsians) found after his discovery, Othniel Marsh changed the name of his specimen to Ceratops. It was not until 1888 when Paleontologist, John Bell Hatcher, discovered a more complete skull of the animal in Wyoming that Marsh officially changed the name to: Triceratops horridus.

Many of the specimens discovered so far, show such variety that an incredibly long list of species began to pile up. In the 1930s, scientists organized these species by joining similar ones together. This resulted in the list of; T. horridus, T. prorsus, T. brevicornus, T. elatus, T. calicornis, T. serratus, and T. flabellatus. In 1983, Paleontologists, John Ostrom and Peter Wellnhofer, co-wrote a paper describing their theory of only one species of Triceratops; T. horridus, suggesting that all the existing species were synonyms of one another. All of the work done on the Triceratops skulls to decide what went to which species was looked into again by Catherine Forster, who hypothesized the existence of only two separate species; T. horridus and T. prorsus. This latest phylogenetic organization is the one that has held up and is widely accepted to this day.

Triceratops’ fossil record does not stop there, nor would it stop here, but one must continue. Torosaurus is another ceratopsian dinosaur of the late Maastrichtian stage of the Cretaceous period (approx. 68–66 MYA) found across the western interior of North America (from Saskatchewan to southern Texas). It lived in the same time and place as Triceratops and, oddly enough, looked remarkably similar. The main difference was Torosaurus’ skull: larger, longer, with twin holes in the middle. Recent findings might suggest the two are one and the same. Paleontologists, John Scannella and Jack Horner, have presented a hypothesis that, since the bones making up the skulls of the two Ceratopsians were metaplastic or ‘stretchy’, the skull might have changed shape as the animal aged. If this is the case and both animals lived in the same time and place and shared remarkably similar physical similarities, Jack Horner and John Scannella suggest that Torosaurus is Triceratops advanced in age past what we recognize as Triceratops. Since the only evidence for synonymy is skull material, there has been debate over Horner and Scannella’s findings. In 2011, Andrew Farke disputed Scannella’s hypothesis by arguing that the fossil record of both animals showcase specimens of Triceratops too old to represent immature individuals and Torosaurus specimens too immature to represent an elder synonym of Triceratops. This debate has yet to end and further specimens are needed before it can be laid to rest.

Triceratops can easily be considered the rhinoceros of the Cretaceous for more reasons than one. It sported three solid bony projections from its skull; two horns above the eyes, and one on the tip of its snout. Triceratops also had a large curved beak like an eagle or parrot. The second most distinguishing feature of Triceratops, minus the horns, is its solid bone frill that sticks out backwards from the skull. Unlike nearly every other Ceratopsian, Triceratops’ neck frill is solid bone and structurally strong. Some specimens have been found to have triangular osteoderms, bone armor under the skin, on the edges of the frill. This may very well point to the idea that Triceratops, and only Triceratops, evolved its frill differently from other Ceratopsians to include both display as well as defensive functions. All other Ceratopsians have holes of varying sizes and shapes in their frills, and some even have preserved impressions of blood vessels, which would point to the use of the frill as a display organ to each other and the world around them. The use of the frill as a defense would also correlate to the three solid horns and presence of crocodile-like osteoderms and scales all over the body, which was recently discovered in mummified fossil skin impressions (Material yet to be scientifically published). The overprotective armor of Triceratops would account for why Tyrannosaurus, the top predator of Triceratops’ ecosystem, had such powerful bone crushing teeth.

Triceratops’ physiology is simple to understand; its mouth held 36–40 teeth packed closely together in batteries. Triceratops’ body was low-slung, and as such, it would have been a muncher of palms, cycads, and ferns. Triceratops took the niche of the low-browser putting it out of competition with the animals of its environment. Triceratops lived with many organisms including; Tyrannosaurus, Acheroraptor, the newly discovered Dakotaraptor, Ornithomimus, Ankylosaurus, Thescelosaurus, Edmontosaurus, and Pachycephalosaurus. Being so widespread across the continent, Triceratops would likely have lived in many different biomes like prairies and open woodlands. The top predator of Triceratops, and most animals in the Hell Creek Formation, was Tyrannosaurus. Tyrannosaurus had especially adapted to take down well-armored prey like Triceratops and Ankylosaurus and would not have too much trouble from sick/dying, old, or young individuals. As an aside, Triceratops is a chasmosaurine, the group of Ceratopsians with usually large open frills and elongated brow horns. The relatives of Triceratops consists of; Torosaurus, Titanoceratops, Arrhinoceratops, Coahuilaceratops, and many more.

Triceratops’ appearance has changed many times over the decades and quite drastically each time. Originally it was depicted as all other members of Dinosauria were; large, slow, squat reptiles that doddled along the bleak landscape looking for their next meal. The original look of Triceratops consisted of a square trunk, tail pointed downwards and dragging, the front limbs squat like a reptile, and the teeth in the mouth fully visible. Then when the Dinosaur Renaissance occurred (1960s-1990s) the thought of Dinosaurs changed from slow moving reptiles to fast moving, warm-blooded ancestors to birds. The look of Triceratops looked close to how it does today with a round body, well proportioned head, arms and legs placed directly underneath the body, with a tail held firmly off the ground. However, new evidence, plus the subsequent anti-shrink-wrapping movement (adding soft tissue to extinct animals as though they are real animals), has changed the idea of the 1980’s Triceratops by adding porcupine-like quills to the rear end of the animal plus crocodile-like scales to the belly and random placement of hexagonal scales around the dorsal side of the animal. Although Triceratops has changed drastically throughout the years, it has continued to stay one of the most popular and well-loved dinosaurs of all time like Tyrannosaurus, Stegosaurus, and Parasaurolophus.

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