1. Education

The 15 Main Dinosaur Types

A Guide to the 15 Major Types of Dinosaurs

By

Dinosaurs came in a dizzying array of types, as you know if you've ever tried to compare a Tyrannosaurus Rex to a Diplodocus. Here are the 15 most important dinosaur types, ranging from ankylosaurs to tyrannosaurs, complete with links to additional information. (See also a complete, A to Z list of dinosaurs and "like" the Facebook page Dinosaurs and Prehistoric Life.)

1. Ankylosaurs

minotaurasaurus
Nobu Tamura

Ankylosaurs were among the last dinosaurs standing 65 million years ago, before the K/T Extinction, and with good reason: these otherwise gentle herbivores were the Cretaceous equivalent of Sherman tanks, complete with armor plating, sharp spikes and heavy clubs. Ankylosaurs (which were closely related to stegosaurs) seem to have evolved their armament mainly to ward off predators, though it's possible that males fought each other for dominance within the herd. Read more about ankylosaurs

2. Ceratopsians

diabloceratops
Nobu Tamura

Among the oddest-looking dinosaurs that ever lived, ceratopsians--"horned faces"--included such familiar dinosaurs as Triceratops and Pentaceratops, and were characterized by their huge, frilled, horned skulls. Most ceratopsians were comparable in size to modern cattle or elephants, but one of the most common genera of the Cretaceous period, Protoceratops, only weighed a few hundred pounds. Read more about ceratopsians

3. Dino-Birds

mononykus
Pavel Riha

During the Mesozoic Era, there wasn't just one "missing link" that connected dinosaurs and birds, but dozens of them: small, feathered theropods that possessed a tantalizing mixture of dinosaur and bird features. Exquisitely preserved feathered dinosaurs like Sinornithosaurus and Sinosauropteryx have recently been unearthed in China, prompting paleontologists to revise their opinions about bird (and dinosaur) evolution. Read more about dino-birds

4. Hadrosaurs

charonosaurus
Luis Rey

Among the last--and most numerous--dinosaurs to roam the earth, hadrosaurs (commonly known as duck-billed dinosaurs) were large, oddly shaped, low-slung plant eaters with tough beaks on their snouts for shredding vegetation. Most hadrosaurs are believed to have lived in herds, and some genera (like the North American Maiasaura and Hypacrosaurus) paid especially close attention to their children. Read more about hadrosaurs

5. Ornithomimids

ornithomimus
Royal Tyrrell Museum

Ornithomimids ("bird mimics") didn't resemble flying birds, but landbound, wingless varieties like modern ostriches and emus. These two-legged dinosaurs were the speed demons of the Cretaceous period; some genera (like Dromiceiomimus) may have been capable of hitting top speeds of 50 miles per hour. Oddly, ornithomimids were among the few theropods to have omnivorous diets, feasting on meat and vegetation with equal gusto. Read more about ornithomimids

6. Ornithopods

muttaburrasaurus
Australian Museum

Ornithopods--small- to medium-sized, mostly bipedal herbivores--were among the most common dinosaurs of the Mesozoic Era, roaming the plains and woodlands in vast herds. By an accident of history, ornithopods like Iguanodon and Mantellisaurus were among the first dinosaurs ever to be excavated, reconstructed and named, putting this dinosaur family at the center of innumerable disputes. Technically, the ornithopods include another type of dinosaur, the hadrosaurs. Read more about ornithopods

7. Pachycephalosaurs

stygimoloch
Luis Rey

Twenty million years before the dinosaurs went extinct, a strange new breed evolved: small- to medium-sized, two-legged herbivores possessing unusually thick skulls. It's believed that pachycephalosaurs like Stegoceras and Colepiocephale (Greek for "knucklehead") used their thick noggins to battle each other for dominance in the herd, although it's possible their thick skulls also came in handy for butting away curious predators. Read more about pachycephalosaurs

8. Prosauropods

massospondylus
Nobu Tamura

During the late Triassic period, a strange, ungainly race of small-to-medium-sized herbivorous dinosaurs sprung up around the world. The prosauropods weren't directly ancestral to the huge sauropods of the late Jurassic period, but occupied an earlier, parallel branch in dinosaur evolution. Oddly enough, most prosauropods seemed to have been capable of walking on two as well as four legs, and there's some evidence that they supplemented their vegetarian diets with small servings of meat. Read more about prosauropods

9. Raptors

raptor
H. Kyoht Luterman

Among the most feared dinosaurs of prehistoric times, raptors were closely related to modern birds, and counted among the dino-birds listed above. Raptors were distinguished by their bipedal postures, grasping, three-fingered hands, larger-than-average brains, and the signature, curved claws on each of their feet; most of them were also covered with feathers. Among the most famous raptors were Deinonychus, Velociraptor and the giant Utahraptor. Read more about raptors

10. Sauropods

supersaurus
Luis Rey

Sauropods were the true giants of the dinosaur family, some species attaining lengths of over 100 feet and weights of over 100 tons. Most sauropods were characterized by their extremely long necks and tails and thick, squat bodies; they were the dominant herbivores of the Jurassic period, though an armored branch (known as the titanosaurs) flourished during the Cretaceous. Among the most well-known sauropods were Brachiosaurus, Apatosaurus and Argentinosaurus. Read more about sauropods

  1. About.com
  2. Education
  3. Dinosaurs
  4. Types of Dinosaurs
  5. Dinosaurs - Guide to the 15 Major Types

©2014 About.com. All rights reserved.