3. it is believed that an asteroid or comet impact caused the extinction of the dinosaurs 65 million years…

3. it is believed that an asteroid or comet impact caused the extinction of the dinosaurs 65 million years ago. what are the two major lines of evidence supporting this theory? the impact of the asteroid caused the atmosphere to be stripped away from earth which killed many plants and dinosaurs. there is a layer of clay at the time of the dinosaurs with high concentration of iridium from asteroids in it, and scientists have found a large impact crater that hit earth 65 million years ago. the dinosaur bones are all radioactive and fractured by the blast of the impact. there is a layer of clay with iridium at the time of the extinction, and there is evidence that new bacteria were brought to earth in the asteroid which infected the dinosaurs.

3. it is believed that an asteroid or comet impact caused the extinction of the dinosaurs 65 million years ago. what are the two major lines of evidence supporting this theory? the impact of the asteroid caused the atmosphere to be stripped away from earth which killed many plants and dinosaurs. there is a layer of clay at the time of the dinosaurs with high concentration of iridium from asteroids in it, and scientists have found a large impact crater that hit earth 65 million years ago. the dinosaur bones are all radioactive and fractured by the blast of the impact. there is a layer of clay with iridium at the time of the extinction, and there is evidence that new bacteria were brought to earth in the asteroid which infected the dinosaurs.

Answer

Brief Explanations:

The key evidence for the asteroid - comet impact theory of dinosaur extinction is the presence of an iridium - rich clay layer (iridium is rare on Earth's surface but common in asteroids) and the discovery of the Chicxulub crater which dates back to 65 million years ago.

Answer:

There is a layer of clay at the time of the dinosaurs with high concentration of iridium from asteroids in it, and scientists have found a large impact crater that hit Earth 65 million years ago.