Epipteral bone

The bones that make up the skeleton of a winged mammal (bird) are called synapophyseal. From the bones of the upper belt of dinosaurs, the humerus and forearm of mammals arose; from the bones of the pigamezotail, the mammal received the femur; From the paleontological remains of mammals came the bones of the human lower limb - the femur and uterus.

In paleontology, the skeleton is called an epipoteral skeleton.

From paleontological material, one can judge the general stages of evolution when the fate of individual groups of spinal bones was decided. Evolution generally proceeded in the direction of development of the structure of the head, limbs and trunk, which led to modification of the skull and skeleton of the chest. This is how cetaceans arose, they appeared from tailed fish with the presence of limbs in their ancestors. At the next stage, the fish, having lost their fins, had their bases in the form of humerus bones and wings - plumage, in this case feathers that performed the function of flight. Due to the decrease in the area of ​​support, the lower part of the hind limbs began to grow and lengthen, the knee joints and femurs began to sharpen, thus turning into vertebrae facing the foot.

An example of evolutionary processes in the initial stages of the development of walking in animals is also provided by phylogenetic and embryonic data on brain morphology, where completely different concepts about the origin of bones are combined. With the help of comparative anatomy and embryology, it is possible to study the features of the evolution of limbs and locomotor functions using the example of individual evolutionarily significant groups of animals.