Affixes

An animal or person exhibiting syndactyly (Greek sun, with) has some or all of the fingers or toes united, either naturally, as in web-footed animals, or as a malformation; brachydactyly (Greek brakhus, short) is the state of having abnormally short fingers or toes; in zoology polydactyly (Greek polloi, many) is the state of having more than five fingers on a hand or toes on a foot.

Words in ‑dactyla are names of orders of hoofed mammals: Artiodactyla (Greek artios, even) comprises those with an even number of toes, such as pigs, camels, deer, and cattle; Perissodactyla (Greek perissos, uneven) comprises those with an odd number, such as zebras, horses, and tapirs. Other systematic names in this ending are obsolete.

The ending ‑dactyl either marks adjectives relating to the state indicated by ‑dactyly or ‑dactyla, or nouns indicating an individual of that nature: polydactyl, syndactyl, artiodactyl, perissodactyl. One example always a noun is pterodactyl (Greek pteron, wing), a fossil warm-blooded flying reptile of the Jurassic and Cretaceous periods. The ‑dactylous ending (see ‑ous) generates adjectives with a similar sense to ‑dactyl, but which are less common: polydactylous, zygodactylous.