phalanx number 1 phalanx_number x phalanx_number N if and only if (i) x is a phalanx, and (ii) x is phalanx number N in a series of phalanges repeated along an prixomo-distal axis, with phalanx_number 1 being the proximalmost phalanx. Note that in humans, the distalmost phalanx has phlanax_number 3, except in ray_number 1, where the distalmost has phalanx_number 2 phalanx_number uberon UBPROP:0000105 Most land mammals including humans have a 2-3-3-3-3 formula in both the hands (or paws) and feet. Primitive reptiles typically had the formula 2-3-4-4-5, and this pattern, with some modification, remained in many later reptiles and in the mammal-like reptiles. The phalangeal formula in the flippers of cetaceans (marine mammals) is 2-12-8-1 proximal_to phalanx