Rib cage
The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates, that encloses and protects the heart and lungs. In humans, the rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human rib cage consists of 24 ribs in 12 pairs, the sternum and xiphoid process, the costal cartilages, and the 12 thoracic vertebrae.
Hero shrew
The vertebrae of the hero shrew are thick, corrugated cylinders. The vertebrae interlock on their sides and lower surfaces. The animal's spine has bony projections that mesh to form a very strong, yet flexible backbone. The differences are especially pronounced in the lower back between the rib cage and hips. The hero shrew has 11 lumbar vertebrae, in contrast to a typical mammal which has 5 such vertebrae. The spine of the hero shrew accounts for 4% of its body weight, in contrast to 0.5–1.6% for a typical small mammal. The ribs of the shrew are thicker than those of similarly sized mammals and the spinal muscles are significantly different. Its abdominal muscles are reduced, while its spinal muscles are enlarged. As a result, the hero shrew has a peculiar gait with its spine flexing in a snake-like manner.