Affixes

A pterodactyl (Greek daktulos, finger) is a flying reptile of the late Jurassic period, a member of an order of such reptiles of the Jurassic and Cretaceous periods, the pterosaurs (Greek sauros, lizard); a pteranodon (Greek an‑, without, plus odous, odont‑, tooth) is a large tailless pterosaur of the Cretaceous period, with a long toothless beak. A pteropod (Greek pous, pod‑, foot), a sea butterfly, is a small mollusc with wing-like extensions to its body which it uses for swimming; pteroylglutamic acid is another term for folic acid, so called because related substances, pterins, occur as pigments in insect wings.