In Hand Museum - Triceratops horridus

The large, horned dinosaur Ticeratops horridus ("horrible three horned face") roamed what is now the American west during the Late Cretaceous Period. Triceratops was a contemporary of T. rex, Gallimimus bullatus and many varieties of hadrosaur. It grew to a length of 9 meters (about 27 ft.), measured 3-4 meters (10-12 ft.) at the top of its back, and weighed as much as 5 tons (about the same as modern African elephants). Two meter (6 ft.) skulls are common among Triceratops specimens and the largest land animal skull ever found, 2.6 meters (8.5 ft.) is from a close relative : Pentaceratops.

Triceratops and their kin are often described as exhibiting herding behavior similar to that found in the grazing mammals of East Africa. Contemporary descriptions show herds of different kinds of plant-eating dinosaurs browsing the Cretaceous landscape on the alert for T. rex and other predators. Triceratops would have used its beak to crop off the low-growing plants that were its food. Like many herbivores now, it did not have binocular vision. Having the eyes on the side of the head allowed them to spot predators in a wider field of vision. Large horns are one of Triceratops most distinctive features. The horn cores on the skull would have been covered with an even larger horn made of tissue similar to your fingernails. These horns were probably used like antlers and horns on modern animals-for combat with other Triceratops over mates or territory, and for defense from predators.

Taxonomy
Triceratops is one of many ceratopsian dinosaurs that proliferated during the Cretaceous, each with its own arrangement of horns and frill. It has been popularized for many years as the arch rival of T. rex, and pictured in numerous "fights to the death". New research by paleontologists is redefining the old image of this remarkable dinosaur.

The taxonomic relationships of dinosaurs are a complicated arrangement full of long Greek and Latin words. This complex system helps us understand which dinosaurs are related to one another as well as the characteristics they have in common. The systematics of a specimen tell the story of its lineage and evolutionary relationships.

Among dinosaurs, Triceratops is an ornithischian and within that group, a marginocephalian (all ceratopsians and pachycephalosaurs are in here). The ceratopsians are further divided into two groups that are defined by specific skull characteristics. Triceratops and its close relatives (Pentaceratops, Chasmosaurus and Torosaurus) all have long, low faces, and horns over the eyes that are longer than the horns on the nose. The other group is characterized by shorter, taller faces, shorter frills and nose horns that were longer than the orbital (eye) horns. In this second group you'll find Styracosaurus, Monoclonius and Centrosaurus. Within its own group, Triceratops is differentiated by not having openings in the bony frill (fenestrae), its frill was relatively short and it had small conical bones along the edge of its frill (epoccipitals).

Anatomy
Like all ceratopsians, Triceratops had large and complex batteries of teeth. The teeth were locked together next to one another along the jaw, as well as, vertically (new teeth pushing up from below or down from above). Rather than grind food, these batteries of teeth (both top and bottom) worked together to chop and slice the vegetation cropped by the animal's beak. As teeth along cutting edge wore out, they were replaced immediately.

The long horns and bony frill are two of Triceratops' most distinguishing characteristics. Fossil remains show both to have many grooves and channels for blood vessels. The presence of these blood vessels raises into question the value of the bony frill as defensive armor. It is now thought that the frill functioned primarily as a display device, as a body heat regulator, and as an attachment point for the massive jaw muscles. The bony horn cores were likely covered by keratin sheaths much like those of modern cows. These sheaths would enlarge and lengthen the size of the horns on a living animal.

Body posture is another area under discussion among paleontologists. Did Triceratops carry their legs straight under the body like mammals or sprawled out to the side like lizards? Current thinking describes Triceratops with straight hind legs that were almost directly under the body. The front legs present the major questions and evidence can be found to support both sides. At the moment the stronger evidence seems to support a semi-sprawling posture. While often depicted with its head held horizontally (horns pointed up), Triceratops more than likely carried its head tipped to the front with its beak down and horns to the front.

[ Dinosauria -> Ornithischia -> Marginocephalia -> Ceratopsia -> Neoceratopsia -> Ceratopsidae ]