These are some of the questions people ask when they come to the museum. If you don't see your question answered here, you might try looking in some of the books listed in our Dinosaur Booklist.

• What was the life span of a dinosaur? We don't know how long these reptiles lived. Large ones probably lived longer than small ones.

• How can you tell male from female? You can't; sexual differences were probably not reflected in the skeleton.

• Do we know what color dinosaurs were? No one knows for sure what color dinosaurs were. Artists make educated guesses based on modern animals when adding color to dinosaurs.

• Are the bones in Dinosaur Hall real? Yes, the bones in the hall are real fossilized bones, except for the skulls, most of which are casts, and an occasional foot bone or vertebra. Most of the bones were excavated in the western United States.

• How heavy are the bones? Very heavy. The fossilization process involves the gradual replacement of minerals of the bone with other minerals, and the filling-in of spaces within the bone with minerals. Displaying these skeletons was quite an engineering feat because of their great weight and often fragile structure.

• Are dinosaurs really extinct? Yes and no. According to the most widely accepted theory, birds evolved from dinosaurs, so some would say birds are living representatives of dinosaurs. However, birds differ from dinosaurs in that they have feathers and other characteristics related to flight, so in that sense, dinosaurs are extinct.

• What caused the extinction of the dinosaurs? Some current theories propose a sudden dying off of dinosaurs. An asteroid or comet impact on the earth or extensive volcanic action might have created so much atmospheric dust pollution that sunlight was blotted out, causing death to plants for several years and, consequently, to animals. Most paleontologists, however, don't believe that a sudden catastrophe doomed the dinosaurs.

  Although many types of organisms became extinct in a relatively short time, many others, such as mammals, birds, and various types of reptiles, fish, and invertebrates survived unaffected. It was alterations in the environment caused by drastic geologic, climactic, and ecological changes that most likely spelled doom for the last of the dinosaurs and the other creatures that became extinct at the end of the Mesozoic Era. But why dinosaurs could not migrate or adapt to changing conditions has not been adequately explained.

For more information about dinosaurs, we suggest that you read some of the books on our Dinosaur Booklist.