sphenodon

from WordNet (r) 3.0 (2006)

Sphenodon
    n 1: coextensive with the order Rhynchocephalia: tuataras [syn:
         {Sphenodon}, {genus Sphenodon}]

from The Collaborative International Dictionary of English v.0.48

Hatteria \Hat*te"ri*a\ (h[a^]t*t[=e]"r[i^]*[.a]), n. [NL.]
   (Zool.)
   A New Zealand lizard, which, in anatomical character, differs
   widely from all other existing lizards. It is the only living
   representative of the order {Rhynchocephala}, of which many
   Mesozoic fossil species are known; -- called also
   {Sphenodon}, {tuatara}, and {Tuatera}.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Sphenodon \Sphe"no*don\, n. [Gr. sfh`n a wedge + ???, ???, a
   tooth.] (Zool.)
   Same as {Hatteria}.
   [1913 Webster]