Expert: Ralph Salier - 2/27/2006

Question
What happened to dinosaurs?

Answer
Hi Dan,

About 160 million years ago the Earth was hit by an astoroid.  This astoroid caused a cosmic winter to occur and all of the large reptilian mega fauna (dinos) couldn't find food, it got cold and they died out and became extinct.  This also caused an ice age to take place and this changed the temperatures of the oceans and the flow of ocean currents and this killed off the large ocean bound reptiles like the plesiosaur.  Only those reptiles like snakes, lizards, turtles etc... which lived in warmer climates and that could live on fat reserves and hide survived.  Other animals like mammels survived because they were small, did not require as much food and could maintain their body temperature so they survived.