Page "Amphibian" Paragraph 45

Amphibians have a skeletal system that is structurally homologous to other tetrapods, though with a number of variations.

They possess a cranium, spine, rib cage, long bones such as the humerus and femur, and short bones such as the phalanges, metacarpals, and metatarsals.

They have four limbs except for the legless caecilians and a few species of salamander.

The bones are hollow and lightweight.

The skeletomuscular system is strong to enable it to support the head and body.

The bones are fully ossified and the vertebrae interlock with each by means of overlapping processes.

The pectoral girdle is supported by muscle and the well developed pelvic girdle is attached to the backbone by a pair of sacral ribs.

The ilium slopes forward and the body is held closer to the ground than in mammals.