Which group of animals has a segmented spinal column together with a few primitive forms in which the backbone is represented by a notochord?

Key Points

• Vertebrata is the group of animals that have a segmented spinal column.
• This group includes not only advanced organisms with a developed backbone but also some primitive forms in which the backbone is represented by a notochord.
• The notochord is a flexible rod-like structure that forms the main support of the body in these primitive organisms.
• Examples of vertebrates include mammals, birds, reptiles, amphibians, and fish.
• The presence of a segmented spinal column is a key characteristic that differentiates vertebrates from other animal groups.

Additional Information

• Vertebrates are part of the phylum Chordata, which is characterized by the presence of a notochord at some stage of development.
• The notochord is replaced by the vertebral column in most adult vertebrates, providing more structural support and protection for the spinal cord.
• Other distinguishing features of vertebrates include a well-developed brain, a closed circulatory system, and an endoskeleton made of bone or cartilage.
• The evolutionary development of the vertebral column has allowed vertebrates to become highly adaptable and occupy a wide range of ecological niches.
• Vertebrates are the most complex and diverse group of animals, with over 66,000 species described to date.