ˈsfēnəˌdän, -fen- noun
Etymology: New Latin, from sphen- + -odon
1. capitalized : a genus of reptiles comprising the tuatara, being distinguished from all other recent reptiles by the presence of a pineal eye, and usually placed with the Rhynchophalia but sometimes segregated in a distinct suborder
2. or spheno·dont -änt -s
[ sphenodont, from New Latin Sphenodont-, Sphenodon ]
: an animal of the genus Sphenodon : tuatara