a greenish-grey lizard-like rhynchocephalian reptile, Sphenodon punctatus, occurring only on certain small islands near New Zealand: it is the sole surviving member of a group common in Mesozoic times
Also called: hatteria
Word origin
C19: from Māori, from tua back + tara spine
tuatara in American English
(ˌtuəˈtɑrə)
noun
either of two primitive, amphibious, lizardlike reptiles (Sphenodon punctatus or S. guntheri) of the SW Pacific, with a row of spines along the back and a well-developed third eye: they are the only rhynchocephalians still in existence