"Pterodactylus is an extinct genus of pterosaurs, whose members are commonly known as pterodactyls." If you aren't prepared to accept that answer, don't expect many to get that correct.
The actual genus name of that particular pterosaur is Pterodactylus. While the term "pterodactyl" is a common name for Pterodactylus, it also commonly refers to every pterosaur including Pteranodon, Quetzalcoatlus, Dimorphodon, Hatzegopteryx etc. Palaeontologists nowadays limit the use of "pterodactyl" to the genus Pterodactylus or any species under the suborder Pterodactyloidea.
In other words, "pterodactyl" is not specific enough to be the answer.
In other words, "pterodactyl" is not specific enough to be the answer.