The vague generic term "pterodactyl" is often used for these creatures. The animals depicted frequently represent either "Pteranodon" or (non-pterodactyloid) "Rhamphorhynchus", or a fictionalized hybrid of the two. Many children's toys and cartoons feature "pterodactyls" with "Pteranodon"-like crests and long, "Rhamphorhynchus"-like tails and teeth, a combination that never existed in nature. However, at least one pterosaur "did" have both the "Pteranodon"-like crest and teeth: "Ludodactylus", whose name means "toy finger" for its resemblance to old, inaccurate children's toys. Pterosaurs have sometimes been incorrectly identified as (the ancestors of) birds, though birds are theropod dinosaurs and not closely related to pterosaurs.