A detailed description of the musculoskeletal apparatus of the shoulder girdle and forelimb of the blunt, bats and furstowings . is given. Particular attention is paid to the identification of specific features of the skeleton and joints. For the main types of locomotion of hairwings and bats, models of movement of elements of the shoulder girdle have been developed. A static analysis of the most important phases of locomotion of these animals. The key features of the structure of the shoulder girdle and limbs of the hornets and bats have been identified, the formation of which provided the possibility of the transition of mammals from ground locomotion to planning and active waving flight. For the first time, the idea was formulated that pre-adaptations that preceded the formation of a wave flight could be associated with two alternating types of locomotion: planning and running along large diameter trunks using widely spaced forelimbs. It is shown that the coatwing is an adequate morpho-functional model of the ancestral stage for bats. An evolutionary ecological-morphological scenario has been developed describing the probable process of successive transformation of the typical parasagittal limbs of the bat ancestor into wings.