Skeleton of a turtle is an artificial creation that resembles the life style and the habits of a turtle. It is made up of wood, fiberglass and other synthetic material and its external appearance is like that of a turtle. Its internal structure is made up of plywood covered with a fiberglass shell, which is attached to a wooden frame. The skeleton acts as a protective shield to protect the internal parts from being damaged or scratched. Therefore, a lot of care is taken in producing them and also they can be painted any color.
A turtle skeleton consists of a carapace, plastron, ribs and flippers. The carapace is a hard, solid cover to the body of the turtle. It encloses the creature’s head, neck, torso and limbs and also helps in the movement of the creature.
The plastron or the front part of the shell is hollow and is used to store food, sand and other things. On the other hand, the ribs or the back portion of the shell serves as the additional seat for the turtle skeleton. These are attached to a wooden frame by means of the plastrons. Each has an independent function, therefore, it is important to distinguish them appropriately. Other materials like nails and hairs may also be attached to the plastron.
The turtle skeleton consists of two main sections namely the carapace or the hard outer shell and the sternum or the soft under surface. Although turtles have evolved so long ago that they hardly have any experience of living in water, they have evolved into such well-developed creatures over a million years. Thus, it is amazing how a turtle can transform into such a perfect copy of its adult self. Their ability to retain their exact size and shape is due to their ability to grow a new shell or to increase the length of their existing shell, hence, resulting to the increase of the plastron and ribs of the turtle.
Even though the exact period of the origin of the sea turtles is still unknown, it is estimated that the first sea turtle was present over the last 220 million years ago. This kind of turtle has been discovered from fossils that were found in the coastal areas of China and Russia. The majority of these fossils belong to the Silurian group, which belong to the same geological period as dinosaurs. They have been discovered in layers which were produced by the flood and gradually covered the earth’s surface. The most recent discovery dates from the Cretaceous geological period.
During the early Cretaceous era, the sea turtles evolved from being a thin-shelled species to a more developed one with bony plates and long legs. The evolution of this turtle probably began after the extinction during the Paleocene geological period. It became a more common sight on the oceans’ surface when the dinosaurs slowly disappeared from the Earth. The turtle started to grow its body size, become more powerful and evolved into a more specialized predator thanks to the evolution of its strong jaws and strong legs. The most obvious sign of evolution in this animal is the presence of bony plates along its back and the complete shell cover.
Its closest relative, the platypus, also evolved into a better predator thanks to the development of its strong jaws and teeth. The platypus has smaller and elongated limbs with a large number of bony plates located in the upper part of its head. All the known turtles have a series of needle-like protrusions attached to their plastrons. These protrusions are made up of several bone fragments and they help in strengthening the turtle’s legs and limbs.
Its tail shape also resembles that of modern-day turtles. The tail shape in all the known reptile family is that of a short dangle; it has two spurlike branches which end in small pointed tips. The spurts of the tail are covered with thick skin, while its roots are very fragile and end with large claws. Thus, the origin of the turtle tail can be traced to the stem-t Turtle.