What is true of the fossil record of mammalian origins?
A) It shows that mammals and birds evolved from the same kind of dinosaur.
B) It includes transitional forms with progressively specialized teeth.
C) It indicates that mammals and dinosaurs did not overlap in geologic time.
D) It includes a series that shows the gradual change of scales into fur.

Question

Quizplus · Accepted Answer

The fossil record of mammalian origins includes transitional forms with progressively specialized teeth, such as the cynodonts, which were reptile-like mammals with teeth that showed a transition from reptilian teeth to mammalian teeth.

Answer: C
 The fossil record of mammalian origins indicates that mammals and dinosaurs did not overlap in geologic time, as the earliest mammals evolved long after the dinosaurs went extinct.

Answers A and D are incorrect. The fossil record does not show that mammals and birds evolved from the same kind of dinosaur, and it does not include a series that shows the gradual change of scales into fur.

What Is True of the Fossil Record of Mammalian Origins