Kiel is ... Why birds need it

Mammals and birds are the vertex of vertebrate evolution. Both of them appeared about the same time. Even in the Triassic period, the very first mammals appeared, which separated from the lizards. They were primitive and did not look like modern animals at all. And at the beginning of the Jurassic period, from the terrestrial pangolins, flying individuals took place, which gave rise to a class of birds.

Reptiles did not occupy all the territory, which allowed the first birds and mammals to settle in free territories. And the fact that they conquered new lands that had not previously been used by the lizards, contributed to the fact that mammals and birds appeared to adapt to survival in a variety of conditions. Lizards are the main competitors, thanks to them the birds developed nervous system, sense organs and behavior. Today we are particularly interested in the question of the structure. We suggest to get acquainted with such part of the body as the keel. This adaptation is in birds and other animals. What is it, what functions it performs, we learn from this work.

Structure of birds

Many birds can fly, some in the course of evolution have lost this ability. Now let's talk a little about the structure of these light and air creatures. Tubular bones saturated with calcareous salt allow the birds to fly, so their skeleton becomes very durable and light. The skull also differs in birds: on the front wall there are only large eye sockets and a beak, which previously was a jaw with teeth.

The neck differs in length and mobility, it has ten to twenty-five vertebrae. Since the forelimbs are the wings, the load on the legs has increased: the bones that form the pelvic part have grown together, so they become much stronger. There are also features in the structure of the humerus, for example - keel. This is a very strong bone, serving as a mount for the pectoral muscles. Let's talk about this a little more.

Keel

As we have already said, the keel is an outgrowth that is necessary for birds to fasten the pectoral muscles. This outgrowth was formed in the process of evolution, since birds can fly thanks to this device, because the pectoral muscles are very developed. It is not only in birds, but also in some animals that have strong forelimbs: as a rule, they dig the earth. An example can serve as a mole. But the keel has a special development in flying birds, bats. There are even so-called keel birds: hummingbirds, swifts and so on. That is, we can say that the keel is a tool for birds and digging animals, without which they simply can not do without.

Functions

The keel is, in birds, mainly the bone growth in the thoracic region, it is flat, it serves to connect the rather strong muscles involved in the movements. Let us highlight the main purpose and functions of this bone process.

• The keel is also needed in order to strengthen the thoracic department, that is, the skeleton in this part is quite strong. We can say that it is an additional tool for protecting vital organs.
• Since birds have quite a lot of muscles during the movement of the wings, the keel is the anchor for such a number of muscle fibers.
• Also, this outgrowth promotes the mobility of the thoracic region. This allows you to make deep movements while breathing.
• The last function is a change in the flight path, the keel occupies far from the last place in this process.

Which birds do not have a keel

So, keel - what is it? We answered this question. It was said that there are outgrowths in birds, but they did not talk about exceptions. It is important to clarify that there is a subclass of ratites. Earlier they were called so:

• Running.
• Ostrich.
• Smooth-chested.

This subclass includes as many as 8 units:

• Casuaro-like.
• Kiwifruit.
• Nandoo-shaped.
• Astute.
• Tynamuiformes.
• Epiornosposobnye.
• Liturnite-like.
• Moa-shaped.

About the last three detachments, many could never hear at all, since their representatives had long since died out.