Serpentes (or offices) commonly indicates the scaly reptiles belonging to the suborder Serpentes. Snakes are among the animals that have always aroused the most interest in humans. This is mainly due to the myths that circulate about their poison and their voracity. Also, we can’t deny that their body shape is a bit odd. These reptiles have no limbs and a certain worm-like appearance. Nonetheless, they have a great range of motion and some of them can reach amazing speeds.
These interesting animals have a close relationship with lizards and blane ashes, in addition to the other animals that form the order Squamata. We already know that lizards are vertebrates, that is, they have an internal bone skeleton. But do snakes have bones?
Characteristics of snakes
To explain if snakes have bones and why it is very important to know them better. These are the main characteristics of snakes:
Cosmopolitan: Although most abundant in warm or temperate locations, snakes are found all over the world and occupy very different ecosystems. There are different types of snakes, such as terrestrial, arboreal, aquatic, and even marine ones.
Body covered with scales: this is a hard and thick coating that is present in all reptiles. Its function is to protect them from extreme environmental conditions, such as the absence of water. The number of scales and their location is specific to each species.
They have no limbs: the ancestors of snakes had limbs, but these disappeared with evolution.
They have no waist : their body is elongated and without moving joints.
Carnivores and predators: they hunt other animals and feed on them. In some cases, they can be considerably larger than they are.
They change their skin: they undress (molt) and form a new one periodically.
They have no eyelids: they always keep their eyes open. They are covered only by a thin membrane of skin that peels off during molting.
Highly developed sense of smell: Their primary sense is smell, although they are also very adept at detecting ground vibrations. Very few have nostrils that detect the heat of their prey.
Poison: Some snakes have venom glands. These serve to paralyze or kill their prey before swallowing them. However, most of these reptiles are snakes that are not poisonous to humans.
Do snakes have bones?
All reptiles are vertebrate animals, meaning their body is supported by an internal skeleton known as the backbone. This is made up of a series of large, flat bones that are joined by intervertebral discs, “pads” formed from cartilage. The function of the spine is to protect and house the spinal cord, a fundamental structure of the central nervous system.
The number of vertebrae will depend on the species and varies from 100 to 500 to which the relative pair of ribs are attached (except for the vertebrae to which the skull is attached). This large number of vertebrae allows the snake to have great mobility and the absence of the sternum, which joins the ribs in other animals, allows a certain elasticity in the movements and “in the expansion of the body”, which happens, for example, to swallow larger prey.
The skeleton of the snake
Now that we know that snakes have bones, we can learn more about their skeletons.
The vertebrae of snakes
The vertebrae of snakes are shorter, wider, and more numerous than those of other reptiles. Although their number depends on each species, they are usually more than 100. As we have mentioned, these are flattened bones that are connected by the intervertebral discs. These discs are relatively flexible and allow for undulation of the body.
The snake belt
In the course of evolution, snakes have lost their pectoral and pelvic girdle (pelvic girdle), although some species have a hint of them. This is the case of boas ( Boidae ) and pythons ( Pythonidae ).
The skeleton of snakes is also characterized by the lack of limbs. Due to their locomotion by means of reptation, these reptiles do not need legs. In the reputation, the body crawls on the ground and is not raised on the limbs, which are missing or rudimentary. The displacement is caused by movements of the whole body, of stretching and constriction alternating with movements of shortening and dilation; or meandering motions and the impediment to retreat, determined by scales, bristles, or other resistant bodies, which grip the ground.
The ribs of snakes
In addition to the vertebrae, snakes have a number of ribs. These are anchored to the vertebrae and ” float ” on the front, as these reptiles have no sternum. Ribs increase the stiffness of the body. This allows them to resist the unevenness of the ground they encounter while moving.
The skull of a snake
Snakes are diapsid animals ( Diapsida ) which means they have developed two “windows” on each side of the skull. The skull also has several bones (about twenty) that make up the skull and jaws. The structure of the jaws is such that the snake can swallow voluminous prey. For example, the lower jaw is not welded anteriorly but only joined with a ligament, which allows the right jaw to move away from the left one, increasing the width of the mouth opening.
Thanks to the elasticity of the skull and jaw, these animals can open their mouths much more than any other reptile and displace the entire skull while eating. Because of this, they can ingest prey much larger than their head diameter.
To inoculate the venom, they have specialized teeth or fangs with which they inject it. These teeth can be grooved (opistoglyphs) and proteroglyphs which have fixed venom teeth, canaliculated and implanted anteriorly on the jaws, or be hollow (solenoglyphs). However, most snakes do not have specialized or venomous teeth.