Question

paleontologists think that tyrannosaurus, sauroposeidon, and other long-extinct theropods and sauropods may have breathed using air sacs connected to tubelike extensions inside the animals’ bones. such structures are found in modern birds, which is why some paleontologists treat the respiratory systems of birds as ______ those of tyrannosaurus, sauroposeidon, and other theropods and sauropods. which choice completes the text with the most logical and precise word or phrase? a. harbingers of b. emissaries for c. proxies for d. subordinates of

Explanation:

To solve this, we analyze each option:

• A. "harbingers of" implies a sign of something to come, but birds' respiratory systems aren't signs of extinct species' systems. Eliminate.
• B. "emissaries of" means representatives, which doesn't fit the context of using birds' systems to understand extinct ones. Eliminate.
• C. "proxies for" means substitutes used to represent or study something else. Since birds' respiratory systems have similar structures to extinct species', they can be used as proxies to study the latter. This fits.
• D. "subordinates of" implies a hierarchical relationship, which is irrelevant here. Eliminate.

Answer:

C. proxies for