Polydactyly or polydactylism (from Greek πολύς (polys) 'many' and δάκτυλος (daktylos) 'finger'), also known as hyperdactyly, is an anomaly in humans and non-human animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes).