Triceratops is a genus of herbivorous ceratopsid dinosaur that lived during the late Maastrichtian stage of the Late Cretaceous Period, approximately 68 to 65.5 million years ago in what is currently North America. It was one of the last non-avian dinosaur genera to emerge before the Cretaceous-Paleogene extinction event. The term Triceratops, which in literal translation means “three-horned face”, comes from the Greek tri, meaning “three”, keras, meaning “horn”, and ops, meaning “face”.
It bears a large and bony frill and three horns on its large four-legged body, and conjuring similar appearance features with the modern rhinoceros, Triceratops is one of the most recognizable of all dinosaurs and the most well known ceratopsid.
Triceratops has been recorded by a number of remains collected since the genus was initially described in 1889, including at least one whole individual skeleton. 47 complete or incomplete skulls were uncovered in just the Hell Creek Formation during the decade 2000-2010. Specimens showing representation of the life stages from hatchling to adult have been discovered.
There has been much debate regarding the function of the frills and the three distinctive facial horns. Traditionally, these have been viewed as a defense mechanism against its predators. More recent theories, noting the presence of blood vessels in the skull bones of coreopsis, find it more likely that these features were mostly used in identification, displays of dominance, and courtship, similar to the antlers and horns of modern mountain goats, reindeer, or rhinoceros beetles.
Individual Triceratops are estimated to have reached around 26 to 29.5 ft in length, 9.5 to 9.8 ft in height, and 13,000 to 26,000 lb in weight. The most unique feature is their sizable skull, among the largest of all land animals. The largest known skull, belonging to specimen BYU 12183, is estimated to have been 8.2 ft in length when whole, and could reach almost a 3rd of the length of the total animal. It bore a single horn on its snout, above the nostrils, and a couple of horns about 3 feet long, with one above each eye. Towards the rear of the skull was a comparatively short, bony frill, decorated with epoccipitals in certain specimens. Most of the other coreopsis had large fenestrae in their frills, while those of Triceratops were obviously solid.
The skin of this dinosaur was strange compared to other dinosaurs. Some skin impressions from an as-yet undescribed sample illustrate that some species might have been covered in bristle-like structures, much like that of the more primitive ceratopsian Psittacosaurus.
Triceratops possessed a strong build, with sturdy limbs and short, three-hoofed hands and four-hoofed feet. Although certainly quadrupedal, the posture of these dinosaurs has long been the topic of some debate. Initially, it was believed that the front legs of the animal had to be sprawling at angles from the thorax, to be able to better carry the weight of the head.
These dinosaurs were herbivorous, and due to their low head, their primary food source was most likely low growth, although they might have been able to knock down taller plants with their horns, beak, and bulk. Their jaws were tipped with a deep, narrow beak, believed to have been better for grasping and picking than for biting.
Their teeth were positioned in groups called batteries, of 36 to 40 tooth columns, in each side of each jaw with 3 to 5 teeth per column, depending upon the size of the animal. This provides a range of about 432 to 800 teeth, of which only a fraction were utilized at any given time. The function of these teeth are to aid in shearing in a vertical to near-vertical direction. The great size and number of teeth of Triceratops proposes that they consumed large volumes of fibrous plant material, with some proposing palms and cycads, and other proposing ferns, which then grew in prairies.
The initial find of Triceratops is a pair of brow horns attached to a skull roof, found close to Denver, Colorado in the spring of 1887. It was sent to Othniel Charles Marsh, who believed that the formation from which it was produced dated from the Pliocene, and that the bones belonged to a particularly large and strange bison, which he named Bison alticornis. By the next year, he realized that there were horned dinosaurs.