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Lesson 5:  Brontosaurus [Bron-ta-sawr-us]
Brontosaurus, also known as Apatosaurus, was the largest dinosaur to walk on all four legs.  Their name, meaning "thunder lizard," was given to them because when Brontosauruses walked the earth shook like thunder with each step.  Like mighty Allosaurus, the Brontosaurus family lived 100,000 million years ago during the Jurassic time period.

Who was Brontosaurus:
On any given day, one could probably find Brontosaurus wading in the deep waters of lakes, ponds and rivers. They stayed here most of the time to protect themselves.  Because they were plant eaters, they had flat teeth that were only good for grinding and chewing.  They had no sharp front teeth to defend themselves from harm.  So the clever Brontosauruses would flee to deep waters where no other dinosaur could swim. In order to stay alive they also had to eat all the time. Because Brontosauruses bodies were so large they ate constantly to feed their strong muscles and bones.


Where was Brontosaurus discovered?

The discovery of the first Brontosaurus (Apotosaurus) fossils were found in Wyoming, Montana and the Rocky Mountains of North America.  The valley in Wyoming is presently named Medicine Valley.   Scientists found the Wyoming remains in the year 1898.


What did Brontosaurus look like?

This large plant eater fed on ferns and conifers, and spent most of their life eating in order to get enough food into their huge body!  Brontosauruses were 69 feet long (twice as long as a regular classroom) and weighed 80, 000 pounds which is more than the weight of 10 full grown elephants.  Brontosauruses could reach food easily by simply stretching out their neck.  Theses long necks made it simple to grab food from plants.  Once able to get enough food they had to swallow it whole. But because Brontosaurus had teeth only in the front it did not allow them to chew. Therefore special pockets on the inside of their mouths allowed them to store the un-chewed food.

The legs of Brontosauruses weighed 570 pounds each because they needed strong legs to hold up their massive bodies.  The neck and tail made up a good deal of its length.  Their tail acted as a defense mechanism against intruders. Brontosauruses long neck was able to see distances far away in order to spot danger.  Despite their small brain which weighed less than one pound, Brontosauruses were pretty smart.  As mentioned earlier, once they spotted other dinosaurs they would make their way into deep waters which other dinosaurs could not stand in.

Brontosaurus Activity