A pterodactyl was a type of dinosaur. They were sharp-teethed, had a distinct shriek, and were capable of stationary hovering in the air.
In 2269, a landing party from the USS Enterprise encountered several mechanized pterodactyls on the Shore Leave Planet. As none from the landing party had thought about pterodactyls, this was a further indication of a malfunction of the planet's master computer. (TAS: "Once Upon a Planet")