Ancestors of hagfish are thought to have been the earliest animals with what?
fossil record antigens backbones antibodies arms feet hairs wings
A B C D E F G H
Vertebrates are animals with backbones, such as horses.
Ancestors of hagfish are thought to have been the earliest animals with backbones
Ancestors of hagfish are thought to have been the earliest animals with what? (A) fossil record (B) antigens (C) backbones (D) antibodies (E) arms (F) feet (G) hairs (H) wings