Frogs often live near water and are amphibians. According to the classification, frogs belong to the amphibian class of Chordata, which can be said to be vertebrates or amphibians. Amphibian is a kind of vertebrate. Besides amphibian, vertebrate also contains many other species. Frogs, as vertebrates, naturally have spines. Although people can't see their spines from the outside, they have spines in their bodies. The main function of spine is to support the body of animals, and the spine of frogs also plays a similar role, supporting the body and allowing them to carry out various life activities freely.

In contrast to vertebrates, invertebrates are animals that have no vertebrae in their bodies. These two kinds of animals are different in many ways except the presence or absence of spine. From an evolutionary point of view, invertebrates belong to a lower class of animals, while vertebrates belong to a higher class of animals because they have spines in their bodies, and they have many advanced body structures that invertebrates do not have.

As mentioned above, frogs are vertebrates with vertebrae. Frogs have not only a spine, but also a skeletal system, so they have bones. Frog bones, like spines, play an important role in supporting their bodies and are indispensable. Without bones, their bodies cannot stand up and they cannot complete various activities. There are more than 30 bones in frogs, which work together. When frogs were tadpoles, they also had bones, but their bones at this time were cartilage, which was not easy to observe from the appearance.