2. critical thinking. although hair is not preserved in fossils, scientists are fairly certain that the first mammals had hair. how can scientists be so certain about this?

3. structures and functions the drawings below show the fossilized skulls of two extinct vertebrates. one of the skulls is from an animal in the group that gave rise to modern reptiles. the other skull is from an animal in the group that gave rise to mammals. identify the group that each skull belongs to, and give two reasons that support your identification.