Which type of animal is characterized by a segmented backbone?

The correct answer pertains to vertebrates, which are animals that possess a segmented backbone, also known as a vertebral column. This structural feature is a crucial characteristic of the subphylum Vertebrata within the phylum Chordata. The segmented backbone provides both structural support and protection for the spinal cord, facilitating a more complex nervous system and allowing for greater mobility and adaptability in various environments.

Vertebrates encompass a wide range of animals, including mammals, birds, reptiles, amphibians, and fish. The presence of a segmented backbone distinguishes them from invertebrates, which lack this structure and generally do not have a skeleton made of bone.

Other categories like amphibians and crustaceans fall under specific classifications. While amphibians are indeed a type of vertebrate, they also possess the defining characteristic of a segmented backbone. Crustaceans, on the other hand, are classified as invertebrates and have an exoskeleton rather than a backbone. Thus, vertebrate is the most accurate choice when focusing specifically on the trait of having a segmented backbone.