The ceratopsids were herbivores, characterized by large bony collars, armed with large bony horns. These dinosaurs are often found in association with hadrosaurs suggesting that they may have had similar habits. Shown here is Triceratops called so for obvious reasons. The head shield, thought originally to be a defensive weapon, is now thought, because of the extensive vascularization evident as vessel channels on the surface of the bony shield, to have been involved in thermoregulation.
Perhaps no otherhas received as much bad press as T. rex, the king of carnivorous dinosaurs. There is little doubt that this carnivore was a fearsome sight, standing 20 feet tall, and having long serrated teeth, apparently capable of ripping its prey to shreds. Its front feet were designed for ripping also and probably were not capable of holding the weight of the animal, which walked upright, using its formidible tail for balance. The most famous T. rex is a dinosaur named “Sue” at the Chicago Field Museum of Natural History. This nearly complete specimen was 43 feet long and stood 12 feet high at the hips.
These medium sized dinosaurs,s, Gallimimus, are the largest of the ornithomimosaurs except for the famous Deinocheirus, an ornithomimosaur with eight foot long arms and 10 inch claws. are best known for their appearance in Jurassic Park, where they featured, as in this picture, as a stampeding herd. The name “Gallimimus” indicates the overall resemblance (mimic) of these birds to chickens (“Ostrich-like”, may be a more diplomatic way to put it). The remains of these forms have been found in Upper Cretaceous strata in Mongolia.
The hadrosaurs or duckbills are herbivorous ornithischian (plant-eating, bird-hipped) dinosaurs characterized by formidible dental “batteries” containing hundreds of interlocking crushing teeth in upper and lower jaws and having broader and more elongate bill-like snouts than other ornithischians. Hadrosaurs have relatively long fore-limbs with hoof-like terminations on the forefeet. Parasaurolophus, depicted here, is further distinguished by the presence of extended nasal cavities above the head. These animals are extremely abundant in some fossil deposits. It is thought that they may have moved in herds, much as sheep do today. Although this point is still controversial, it is apparent that Hadrosaurs could walk upright, and probably on “all fours” as well. Just which method was preferred awaits further study, but many trackways thought to have been formed by hadrosaurs show only rear foot impressions.
Pterosaurs, or flying reptiles, are not, strictly speaking dinosaurs, although they were contermporaries, and doubtless lived in similar habitats. These reptiles were apparently not just gliders, but were capable of active flight as well. In 1975, the largest pterosaur ever found came to light in Big Bend National Park, in Texas (of course!) . This monster had an estimated wingspan of about 35 feet, as large as that of some jet fighter planes. Other pterosaurs, perhaps juveniles, were only a few cenitmeters tall, but appeared to be capable of flight. These reptiles typically had an impressive mouthful of teeth.
The raptoral dinosaurs, typified by this version of Utahraptor, achieved great notoriety in the movie “Jurassic Park”, where they were depicted as fierce, aggressive predators. While this is just speculation, we can discern in the skeletal remains from which this depiction originated, the possibilities for an aggressive carnivorous creature.
The sauropods were the blue whales of the dinosaur world. They were herbivores identified by their extremely large bodies, up to 120 feet in length. They had very small heads at the end of long necks, and bore their nostrils on the tops of their heads, which has fueled the suggestion that they lived in water.
All animations, pictures and explanations on this page complements of Earth History Research Center.