Self-study
Most land-dwelling vertebrates have rotating limbs terminating in digits, a characteristic useful for land movement. ██████████ ███ ██████ ████ ████ ██████████████ ███████ ████ █████ ███████ █████████ ███████ ████████████ ████ ████████ ███ █████████████ █ █████ ██████████ ████████ ██ ███ ████ ████████████ ██ █████████ ████████ █████ ███████████ ██ ███████ ███ ███ ████████ ███ ███ ██████ ███ ████ █████████ ██ ████ ████████ █████ ████ ████████ ██████ ██████████ ████ ██ ███ ███ ████████████ ████ ███████████ ████████
Summary
Most land-dwelling vertebrates have rotating limbs with fingers, a feature useful for land movement. The Acanthostega, a newly discovered ancestor of all land vertebrates, possessed rotating limbs with fingers, but its skeleton was too feeble for land movement. The Acanthostega breathed using only internal gills, indicating that it was exclusively aquatic.
Strongly Supported Conclusions
Some physical features common to certain aquatic animals are useful for land movement.
24.
The statements above, if true, ████ ████████ ███████ █████ ███ ██ ███ ██████████
a
Many anatomical characteristics ██████ ██ ████ ████ ███████ █████████ █ ████████████ ███ ████████ ███████████
This answer is unsupported. We only know that rotating limbs with fingers are common to most land animals. To say that there are “many” characteristics in common with most land animals is too strong.
b
None of the ██████████ ███████████████ ██████ ██ ████ ███████ ███████ █████████ ██ █████████ ███ ████████ ██ █████
This answer is unsupported. We don’t know anything from the stimulus about the physical characteristics of most aquatic animals. We only know that the Acanthostega had rotating limbs with fingers.
c
Acanthostega originated as █ █████████████ ████████ ███ ███████ █████ ████ █████ ██████ ██ ██ ██████████ ████████████
This answer is unsupported. We don’t know where the Acanthostega species originated from the stimulus.
d
All anatomical characteristics ███ ██████ ███ ████ ████████ ███ ██████ ██ ████ ████ ███████ █████████ ██ █████████ ███ ████████ ███████████
This answer is unsupported. We don’t know from the stimulus if there are characteristics common to most land animals that are useful for surviving underwater. We only know that most land animals have at least one feature that is useful for land movement.
e
Certain anatomical characteristics ██████ ██ ████ ███████ ███████ █████████ ██ █████████ ███ ████████ ██ █████
This answer is strongly supported. We know from the stimulus that the Acanthostega had rotating limbs with fingers, a characteristic useful for land movement, even though this species was exclusively aquatic.