[Carpal bones of the Chiroptera in the comparative-anatomical and functional aspects].
Data on investigation of hand sceletal bones carried out in eight genera of three families of bats were subjected to comparative-anatomical and functional analysis. Quantitatively, the hand sceletal bones of Chiroptera preserve constructive pattern general for the hand of terrestrial mammalians Pentadactilus. It has rudiments of the prefirst (Pp) and the seventh (Pm) rays. The latter is situated on the volar surface of the base Mc5. Scaphoid, semilunar and central carnal bones of Chiroptera, like those of Mototremata, some Marsupialia, Insectivorona and Carnivora merge together into one large bone--os lunatum. At the same time, the hand of Chiropter is a highly specialized structure, that is evident from the presence of articular restricotrs of anterior sagging of the wrist, crests and grooves directing movements in a strictly definite plane, from fan-like spreading and bringing together the rays, from very long metacarpal bones and proximal phalanges, from reduction of distal phalangs of the 3d and 5th fingers. Thus, the hand of Chiroptera is a unique example of combination of primitive, initial for pentadactule plantigrades wrist with signs of narrow specialization resembling, to some extent, those of Ungulata; only in Ungulata those signs developed on the base of digitigrades wrist.