Which of the Following Could Be Considered the Most Recent

Question

Which of the following could be considered the most recent common ancestor of living tetrapods?
A) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates
B) an armored, jawed placoderm with two pairs of appendages
C) an early ray-finned fish that developed bony skeletal supports in its paired fins
D) a salamander that had legs supported by a bony skeleton but moved with the side-to-side bending typical of fishes
E) an early terrestrial caecilian whose legless condition had evolved secondarily

Accepted Answer

The sturdy-finned, shallow-water lobe-fin with skeletal supports similar to those of terrestrial vertebrates is believed to be the most recent common ancestor of living tetrapods. This is based on both molecular and fossil evidence, as lobe-finned fishes are known to have given rise to the first tetrapods during the Devonian period.