How do the phalanges (finger bones) and metacarpals (hand bones) differ in these vertebrates?
All vertebrates have the same basic template of bones; this is expecially obvious in the versatile pentadactyl limb. “The forelimb has been successfully adapted in mammals of all sizes and in terrestrial, arboreal, aquatic, and airborne environments. In primates, the forelimbs have developed such that speed and stamina have been sacrificed for an increased range of movement, which in turn has provided increased manual dexterity. ” “Ungulates (hoofed mammals including horses)), on the other hand, have evolved to maximize speed and stamina in quadrupedal locomotion. The two main orders of ungulates have elongated phalanges and metacarpals; all ungulates have lost the first metacarpal. ” “The bat’s forelimb is adapted for flight. The humerus is short relative to the longer, slender radius; the ulna is reduced and not part of the wrist joint. The metacarpals and phalanges provide a light but strong frame over which the skin is stretched, much as the silk of a kite covers its frame.
