Hand of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand. The human hand normally has five digits: four fingers plus one thumb; these are often referred to collectively as five fingers, however, whereby the thumb is included as one of the fingers. It has 27 bones, not including the sesamoid bone, the number of which varies between people, 14 of which are the phalanges (proximal, intermediate and distal) of the fingers and thumb. The metacarpal bones connect the fingers and the carpal bones of the wrist. Each human
Hand precise working organ enabling gestures — the expressions of our personalities. There are nevertheless several primitive features left in the human hand, including pentadactyly (having five fingers), the hairless skin of the palm and fingers, and the "os centrale" found in human embryos, prosimians, and apes. Furthermore, the precursors of the intrinsic muscles of the hand are present in the earliest fishes, reflecting that the hand evolved from the pectoral fin and thus is much older than the arm in evolutionary terms. The proportions of the human hand are plesiomorphic (shared by both ancestors and extant primate species); the elongated