During chordate evolution, which of the following structures arose first?
A) paired fins
B) jaws
C) four-chambered heart
D) amniotic egg

Question

Quizplus · Accepted Answer

Paired fins are considered to have arisen first in the evolutionary history of chordates, predating the development of jaws, four-chambered hearts, and amniotic eggs. These structures are seen in early fish, which are among the earliest chordates.

During Chordate Evolution, Which of the Following Structures Arose First