Which of these would a paleontologist be most likely to do in order to determine whether a fossil represents a reptile or a mammal?
A) Look for the presence of milk-producing glands.
B) Look for the mammalian characteristics of a four-chambered heart and a diaphragm.
C) Because mammals are eutherians, look for evidence of a placenta.
D) Use molecular analysis to look for the protein keratin.
E) Examine the teeth.

Question

Quizplus · Accepted Answer

Examining the teeth is the most reliable way to distinguish between reptiles and mammals in fossils because they have distinct dental characteristics. Reptiles have homodont teeth, whereas mammals have heterodont teeth, which are specialized for different functions such as cutting, grinding, and tearing.

Which of These Would a Paleontologist Be Most Likely to Do