Jellyfish have been on Earth for over 650 million years,
before sharks and dinosaurs.
Dinosaurs lived on Earth for around 165 million years before
they became extinct.
Most dinosaurs lived to be more than a hundred years old.
The first dinosaur, the Staurikosaurus appeared around 225
or 230 million years ago.
Archaeopteryx was a small creature with feathers that could
fly and shows that birds are descended from dinosaurs.
Some dinosaurs had tails up to 45 feet long.
The smallest dinosaur is the Compsognathus and it was about
the size of a basketball.
The largest dinosaur was the Brachiosaurus.
There were about 400 - 500 different kinds of dinosaurs in
Time and erosion have erased 99 percent of all dinosaur