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
Guide to Dinosaurs and Prehistoric Reptiles]