Definition that contains order rhynchocephalia
- sphenodon coextensive with the order Rhynchocephalia: tuataras
- sphenodon punctatum only extant member of the order Rhynchocephalia of large spiny lizard-like diapsid reptiles of coastal islands off New Zealand
- tuatara only extant member of the order Rhynchocephalia of large spiny lizard-like diapsid reptiles of coastal islands off New Zealand
- genus sphenodon coextensive with the order Rhynchocephalia: tuataras