The spelling. I think the one whose name ends in “n” was the biggest flying reptile yet discovered. I also seem to remember that one of them had a tail.
Pterodactyl is kind of a generic word for that encompasses both the pterodactyls and the pteranodon . So in other words a pteranodon is a pterodactyl, but a pterodactyl isn’t necessarily a pteranodon.
@SavoirFaire Pterydactyl is a common word for winged reptiles. Yes, the proper term is pterosaur, but regardless of how much scientists dislike it, it is a word and it covers the order Pterosauria. I was simply answering the question “What’s the difference between a pteranodon and a pterodactyl?”. But if you prefer, a pteranodon is a pterosaur, but a pterosaur isn’t necessarily a pteranodon.
@AstroChuck There’s a difference between calling something a common word or a colloquialism and calling it a generic word. Saying it is a generic term implies that is proper. If you had just said that it was a common word, or that it was a colloquialism, you would have gotten no argument from me. I don’t disagree, after all, that people use the word “pterodactyl” to refer to both (mistaken as it may be).