(teratology) polydactyly and syndactyly in the same hand or foot
(biology) The normal condition, in some animals and birds, of having fused digits.
Polysyndactyly is an hereditary anatomical malformation combining polydactyly and syndactyly. There is also a type called crossed polysyndactyly.
(teratology) The anomalous condition, in humans, of having some fingers or toes fused with a web.
birth defect in which there is partial or total webbing connecting two or more fingers or toes
Syndactyly is a condition wherein two or more digits are fused together. It occurs normally in some mammals, such as the siamang and diprotodontia, but is an unusual condition in humans.