(of a vertebrate limb) having three toes or fingers.
- ‘In the foot, the fifth toe was reduced to a single metatarsal, and the first toe was reduced and raised off the ground, leaving a functionally tridactyl foot.’
- ‘The foot is functionally tridactyl, with digits II - IV bound together and largely functioning as a single unit.’
- ‘Ornithopod prints are nearly always tridactyl with three stout and broadly spreading toes so that the resulting footprint has the outline of a trefoil.’
- ‘Podokesaurid (= Coelophysid) theropods are indicated by the presence of numerous small to medium-large sized tridactyl footprints (Grallator and larger forms).’
Early 19th century: from tri- ‘three’ + Greek daktulos finger.