A cat is a vertebrate, placing the domestic cat, Felis catus, within the biological subphylum Vertebrata. This classification is based on core anatomical structures shared across a vast group of animals. Understanding this designation is fundamental to grasping the cat’s physiology, including its movement capabilities and nervous system organization.
What Defines a Vertebrate
A vertebrate is defined by the presence of a vertebral column, or backbone, which is the defining feature of the subphylum Vertebrata. This column is composed of individual bony or cartilaginous segments called vertebrae. The segmented structure of the vertebral column provides both support for the body and flexibility for movement.
Vertebrates also possess a distinct skull, or cranium, which is a bony or cartilaginous structure that encases and protects the brain. Furthermore, these animals have a closed circulatory system, where blood is contained within vessels and pumped by a muscular, chambered heart. These criteria—the vertebral column, the cranium, and a protected nervous system—form the biological standard for this group.
Anatomical Evidence in the Cat
The domestic cat meets the criteria for a vertebrate through its specialized skeletal and nervous systems. The feline spine consists of 52 to 53 individual vertebrae divided into five distinct regions, including seven cervical vertebrae in the neck. This segmented spine provides the flexibility and range of motion characteristic of the species, allowing for their agility.
The vertebrae surround and protect the spinal cord, the main pathway of the central nervous system. Elastic discs sit between each vertebra, acting as shock absorbers important for cushioning the impact of a cat’s jumps and landings. The cat’s skull is a compact structure composed of approximately 29 bones that protect the brain and house sophisticated sensory organs. This intricate bony structure confirms the presence of a cranium.
Classification of the Domestic Cat
The classification of the domestic cat begins at the Phylum Chordata, which includes all animals possessing a notochord, a dorsal nerve cord, and pharyngeal slits at some point in development. Vertebrates are a subphylum within Chordata, distinguished by the replacement of the notochord with a vertebral column during development.
The cat is further classified into the Class Mammalia, a group characterized by features such as hair, the ability to produce milk via mammary glands, and three middle-ear bones. This taxonomic placement differentiates the cat from invertebrates, such as insects or mollusks, which lack internal skeletal structure or bony protection for their nervous system. The scientific name is Felis catus.