(ah-PAT-uh-sawr-us)
Restored in line with current thinking, an Apatosaurus walks with its tail held clear of the ground. This stopped other sauropods treading on its tall, and may also have prevented hunting groups of small theropods from seizing it.
One of the largest dinosaurs that ever walked the earth, Apatosaurus appeared around 155 million years ago and was a member of the great sauropod (four-legged plant eater) family.
As shown below, Apatosaurus might have reared up on to its hind legs to threaten a large, marauding theropod that was endangering its young. But not all scientists believe that sauropods adopted tactics like this. Perhaps these enormous creatures intimidated their enemies by closing their ranks and relying on sheer size and tough hides for protection.
All sauropods had stiff limbs and thick legs. Animals like these were slow, lumbering beasts that spent most of their lives eating leaves and large plants. Big animals need a lot of food to satisfy their hunger, and dinosaurs were no exception.
Apatosaurus was once called Brontosaurus, or "thunder lizard," because people assume it must have shaken the earth when it walked. After all, it did weigh more than 30 tons.Apatosaurus had a very long neck that stretched more than 20 feet from its shoulder to its head. Scientists used to think the head was small but recent discoveries have shown it to be quite large. It had small teeth shaped like pegs and spent a long time chewing its food. Because these dinosaurs had small brains, scientists used to believe they were stupid. Modern scientists now suspect that they were more intelligent.
Location:
USA Colorado, Utah, Oklahoma, Wyoming
Mexico Baja, California
This massive beast was 21 metres nose-to-tail, five metres high at its hips, and weighed 30 tonnes. Some of its fossils were once named Brontosaums, but all specimens are now called Apatosaurus, or "deceptive reptile" -a good name for a dinosaur that confused the experts.
Diet: Tree leaves, fern
Size: Length- 21metres (69ft) Weight- 25 tonnes
Classification:
Family- Diplodocidae
Infraorder- Sauropoda
Suborder- Sauropodomorpha
Order- Saurischia
Time: 156-150 million years ago