The Structure of Frog Vertebra

Frogs have a skeletal structure similar to humans, it is just less complex. One of the main places this can be observed is the vertebrae. While a human skeleton is made up of twenty-four vertebrae, a frog only has nine complete ones. There is a tenth that is incomplete. Also like a human, the vertebrae serves many purposes.

  1. The Atlas

    • The atlas is the first vertebrae of a frog, laying right underneath the base of the skull. The joint that is formed here is responsible for fifty percent of the head movement. This vertebrae is what allows a frog to move its head in an up and down motion. The atlas is also the only cervical vertebrae in a frog. A cervical vertebrae is what creates the neck, so the frog can only move its head in the one small motion the atlas allows.

    The Abdominal Vertebrae

    • A frog has only four to seven abdominal vertebrae, depending on their size. These connect the limbs to the front of the body, while also supporting the organs within the abdominal cavity. These vertebrae also have zygapophyses coming from them, which look a lot like small, straight ribs. Because of this, a frog can only bend a very small amount side to side.

    Postsacral Vertebrae

    • The urostyle, or postsacral vertebrae, is the last one in a frog. This is much longer than the others and modified from other amphibians. Most amphibians have more vertebrae in the postsacral section, but in a frog they are fused into one.

    Anurans

    • Frogs are anurans, or simply tail-less. Other amphibians have a final vertebrae section that would be called the caudal vertebrae. But because the frog has a body built for jumping and not walking, it no longer has a need for the tail. This is true of toads as well.