What structural features indicate that the ancient phomas of the lancelet were close relatives of vertebrates.

The lancelet is characterized by the fact that in its structure there is a notochord throughout its life. This is the dorsal axial cord, which performs the function of maintaining the shape of the body. The lancelet, respectively, belongs to the chordate type. In the course of evolution, vertebrates received a stronger and more functional spine. But humans, like other vertebrates, are chordates. We have a chorda only at the stage of embryonic development. It transforms into other organs. Therefore, the lancelet and vertebrates are very close from an evolutionary point of view.