What Really Killed the Dinosaurs

Some Scientists Think they were on their Way to Extinction Before the Meteorite Hit

by Giselle Sanchez, age 11

Do you know why the dinosaurs disappeared? Some people think it was because of a meteorite that hit the Earth 65 million years ago. But scientists believe that dinosaurs started to die off before the meteorite hit.

Scientists found fossils in Alberta, Canada in the rocks of the Judith River. These fossils come from at least 32 different kinds of dinosaurs from about 75 million years ago. In of Hell Creek in Montana fossils were also found in younger rock from 65 million years ago. Here, they found only 19 different of dinosaur fossils. Scientists suggest the drop in number means the dinosaurs could have disappeared before the meteorite hit the earth.

One dinosaur fossil that was found was a Cretaceous Armored Dinosaur called the Ankylosaurus . The Ankylosaurus was one of the last armored dinosaur to survive. It weighed four tons and was as long as 16 feet from tip to tip. The dinosaur had thick bands of big heavy armor that ran down from the tip of its tail.

Another kind of dinosaur that paleontologists found was a Cretaceous Duckbilled Dinosaur called the Edmontosaurus . A lot of scientists have come across many skulls of these flat-headed creatures. They had toothless beaks, but behind their jaws were more than 1,000 packed teeth. Having this number of teeth made eating tougher plants easier. Its long tail helped it balance when it stood on its back legs. The Edmontosaurus ’ long tail was also very helpful for swimming.

It was at the end of the cretaceous period that dinosaurs disappeared forever. Although nobody knows for sure whether they became extinct before or after the meteor hit Earth 65 million years ago, it is clear that they began declining before the meteor hit.

[Source: The Complete Guide to Dinosaurs and Prehistoric Reptiles ]