Question

Which of these would a paleontologist be most likely to do in order to determine whether a fossil represents a reptile or a mammal?

1) Look for the presence of milk-producing glands.
2) Look for the mammalian characteristics of a four-chambered heart and a diaphragm.
3) Because mammals are eutherians, look for evidence of a placenta.
4) Use molecular analysis to look for the protein keratin.
5) Examine the teeth.

Answer 1

A paleontologist would be most likely to examine the teeth to determine whether a fossil represents a reptile or a mammal.

Option 5) Examine the teeth is correct.

Step-by-step explanation:

Teeth are often crucial indicators in distinguishing between reptiles and mammals. Reptiles typically have homodont dentition (similar teeth), while mammals exhibit heterodont dentition with specialized teeth like incisors, canines, molars, and premolars. Mammals often possess distinct dental characteristics related to their specific dietary habits, providing valuable information for paleontologists studying fossilized remains. Options 1, 2, and 3 involve features specific to mammals but might not be as readily preserved in fossils. Molecular analysis (Option 4) is more applicable to recent species, as DNA degradation limits its usefulness in ancient fossils.

Option 5) is the answer: