Which of the following statements would be least acceptable to most zoologists? a) the first fossils resembling lancelets appeared in the fossil record around 530 million years ago. b) recent work in molecular systematics supports the hypothesis that lancelets are the basal clade of chordates. c) the extant lancelets are the immediate ancestors of the fishes. d) lancelets display the same method of swimming as do fishes.

The answer is: C. The extant lancelets are the immediate ancestors of the fishes.

What differentiate lancelets and the fishes is the existence of the bones. Lancelets have none while fish has it. Most of the zoologists would most likely see lance lets as the contemporaries of fishs due to the similarities that they both have. This happen because it is least likely that ancestors of a certain organisms could live in the same time period as the more evolved organisms.