Tetrapod (消波塊)

thingiverse

The tetrapod structure is a fundamental concept in biology that refers to the arrangement of bones in the limbs of four-legged animals. This structure is characterized by the presence of four limbs, each consisting of a limb bone and a set of digits. The tetrapod structure evolved from a common ancestor with fish-like creatures, which had fins instead of limbs. Over time, these early tetrapods adapted to life on land and developed more complex limb structures, including the development of hands and feet. Today, tetrapods can be found in various forms, ranging from amphibians like frogs and salamanders to reptiles like snakes and lizards, as well as mammals like humans and dogs. Despite their differences, all tetrapods share a common ancestor with fish and are characterized by the presence of four limbs.