Approximately time passes between B and F

Coquina, a type of limestone, forms from shell fragments that settle on the ocean floor. what type of rock is coquina?

Up until 1938, paleontologists accepted the idea that coelacanths (an ancient fish) went extinct at the time that they last appear in the fossil record, about 80 million years ago. but in 1938, a live coelacanth was discovered off the coast of south africa that was compared to the fossil record and found to be the same species what goal of science does this discovery represent

To be or not to be that is da question