Refer to the figure. Why do some biologists consider the term "craniates" more appropriate than "vertebrates" in referring to the group that includes hagfishes along with the rest of the vertebrates?

Question

Refer to the figure.  Why do some biologists consider the term "craniates" more appropriate than "vertebrates" in referring to the group that includes hagfishes along with the rest of the vertebrates?

Quizplus · Accepted Answer

The term "vertebrates" implies that all members of the group have bony vertebrae or a backbone. However, hagfishes lack true vertebrae and instead have skeletons made of cartilage. Therefore, some biologists prefer the term "craniates," which refers to all members of the group that have a skull or cranium, including hagfishes and all other vertebrates. In other words, the term "craniates" is more inclusive and accurate than "vertebrates" when discussing this group of animals.

Refer to the Figure